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95 Cards in this Set

  • Front
  • Back
What are the seven components of a computer network?
Hardware: PCs and network servers
Networking hardware hub
Media: twisted pair wire
Communication software: network client and network operating systems
Protocol: Ethernet
Provider
Application: i.e. Outlook
What's the difference between a router and a switch?
Router connects networks
Switch connects computers and creates a LAN
What are a couple examples of wired and wireless media? What's the relative speed of these?
Wire: Coaxial cable - 200mps... optical fiber 40gbps

Wireless: 802.11x...a 11mbs...g 54mbs... n 200mbs
Whats the difference between a LAN and a WAN?
LAN - Local Area Network: a network where computers are within a single department or building
WAN - Wide Area Network: a network that covers several buildings or cities (ex. internet)
What is the Carrier Sense Multiple Access and Collision Detection (CSMA/CD) protocol used for and how does it work?
NIC checks to see if media is idle, if so NIC transmits fram and listens for collision, if NIC detects collision with frame of another NIC, it waits a present amount of time and retransmits frame.

Characteristics:
-good with lower traffic volume
-reduces network overhead and increases efficiency
-availability of bandwidth is uncertain
What is the difference between circuit switching and packet switching? Why is is packet switching considered to be more efficient?
Circuit Switching
-Used for phone calls and leased lines for data communication
-Continuous transmission, dedicated circuit
-Can be monitored
-Can determine length of transmission

Packet Switching:
-Packet: collections of bits that are part of a message plus other information
-Router: hardware that moves packets
-Intermittent transmission
-Non-dedicated
-No center and no controller
-Hard to monitor, control and keep status information
What is the difference between the Internet and the Web? Which on is "bigger"?
Internet is a network of networks defined by protocols

Internet hosts the web plus, VoIP, FTP, SFTP, IRC, Streaming audio and video, Telnet, ssh, File Sharing protocols etc.

Web: collection of documents and applications accessible via the http protocol
What is HTTP used for?
Used for sharing documents over the internet
What does and IP address look like? How does it relate to a URL?
IP (Internet protocol): 141.221.144.23

Like a URL because it is an address, state.city.street.house

URL is the domain name
What's a domain name?
A human friendly name of internet servers
What does a domain name server (DNS) do?
Maintains table of domain names and related IP addresses

Converts domain names into IP addresses
Parts of a URL
http://www.umich.edu/~regoff/index.html

HTTP: protocol
edu: top level domain
www.umich: sub domain
~regoff: directory
index.html: file
Who owns and controls the internet?
No one owns the internet
What's a client? What's a server
Client: dependent computers on the server because the server contains most of the data and software

Server: acts as the central storage location for a program and provides mass storage for most of the data used on the network
What's the benefit of client/server computing vs. single tier (client only) computing?
Accessibility from multiple access points (different computers)

Collaboration capabilities: multiple users editing same file from different locations simultaneously ex. google docs
Provide and example of client/server computing. Describe how a Web site serves as an example of client/server computing.
UM computers connected to the network...
What are the two different types of software?
Application software: Satisfies specific user needs (MS Office)...helps user carry out a variety of tasks

Systems software:
-Makes hardware usable
-Helps computer carry out its basic operating tasks
-Manages the fundamental operations of your computer such as loading programs and data into memory, executing programs, saving data to disks, displaying information on the monitor, and transmitting data through a port to a peripheral device
Why does your computer have an operating system? What functions does it handle? Why do we care about what operating system a computer has?
Operating system:
-controls basic input and output
-provides functions needed by many applications
-handles simultaneously program execution
-manages resources: RAM and disks
-File management
-Monitor performance
-Monitor security
-Provide tools for creating user interfaces
-Detects equipment failure

We care because they provide different features, programs are written for specific OS

Used to be proprietary
What are the different ways in which a computer can handle simultaneous execution?
Multi-tasking: multiple processes (two or more programs) share same CPU

Multi-threading: two or more tasks within one program at the same time

Multi-processing: using two or more central processing units
Why do we care about how well a computer can handle simultaneous execution?
Helps us work faster and more efficiently
What is virtual memory? How does it work? Why do we care if an operating system has it?
Virtual memory allows a computer to act as if it has more memory than it actually does when the computer uses all the available RAM

If your computer is running out of RAM from one program and you open a new program, the operating system will move the least-used segment of the program into virtual memory on disk to allow the new program to be loaded into RAM

If the least-used segment is then needed, it is copied from virtual memory back into RAM and the new least-used segment is moved to virtual memory

Virtual memory allows us to execute many more applications at once

Disadvantage: using virtual memory is much slower than RAM, so expanding RAM capacity will improve performance
From the user's point of view, what's the difference between running a compiled program and running an interpreted program?

Why would the programmer care about this difference?
Compiler: translates all the program source language statements into a file containing machine language (code) which is later processed y the CPU in a separate execution step

Interpreter: translates one program source language statement into machine language and passes it to the CPU for execution before proceeding to the next instruction

You generally don't have a choice whether to compile or interpret for a specific language

C programs are compiled while Perl is interpreted and Java can be either
What is the relationship between software and open source software (OSS)?
OSS is a type of software, free, modifiable, product of community.

-a new way to develop and distribute software
-No owner
-Sharable: Product of community
What does the concept of "free" have to do with OSS?
Free: make source code of program available to anyone and everyone
Freeware vs. proprietary vs. shareware vs OSS software
Proprietary software (can be freeware and shareware): has restrictions on using, copying, and modifying as enforced by the proprietor (can involve software licensing, copyright, patents)

Freeware: copyrighted computer software that is made available for use free of care for an unlimited time
-Often want to give something to community, but also wants credit for their software and to retain control of its future developments

OSS: any computer software whose source code is available under a license that permits users to study, change, and improve the software and to redistribute it in modified or unmodified form
-Often developed in a public, collaborative manner
Can an operating system be open source? examples?
Yes, Linux and Chrome OS are open source
Is it possible to make money with OSS?
Yes by selling support and related services.

ex. accessories (books and shirts),

widget frosting: if you make and sell hardware, go open source with software

Loss leader: give away some software as a loss leader to draw attention to your other software
What does a processor do? What distinguishes one processor from another?
-Processors do actual calculations related to numbers, text, video, audio
-32 or 64 bit (how many bits it can process at once)
What factors influence computer speed?
Processor instruction set: kinds of operations a computer can perform and processors from different vendors have different instruction sets

Processor clock speed

Bus speed: BUS is a collection of wires through which data is transmitted from one part of a computer to another

Bus width

Memory speed
What's Moore's Law?
The number of transistors on an integrated circuit doubles every 18 months
What's the relationship between the motherboard and processor?
Motherboard:
-main circuit board of the computer.
-Contains the processing hardware, the computer's major electronic components

Contains:
-specialized chips ex. video, audi
-Slots for expansion cards (for capabilities not offered by motherboard
-Ports for connecting peripherals

Processor
-an integrated circuit which is located on motherboard
-responsible for executing instructions to process data
How can the speed on one computer be compared with the speed of another?
Clock speed: the pulse of the processor (measured in MHz or GHz)

Word size: the number of bits that are processed at one time (64 bit faster than 32)

Cache (RAM cache or cashe memory): Special high-speed memory reserved for the microprocessor's use
-speeds up the processing function by accessing data the computer anticipates you will request soon, while you are working on something else
What is a mainframe?
a mainframe computer is typically used to provide centralized storage, processing, and management for large amounts of data
What are the three kinds of input devices?
Keyboard
Mouse
Pointing devices
What are four features that distinguish one monitor from another?
CRT (Cathode ray tube): uses gun-like devices that direct beams of electrons toward the screen to activate dots of color to form the image you see

LCD (Liquid Crystal display): creates the image you see on the screen by manipulating light within a layer of liquid crystal

Factors that influence quality of monitor are screen size, resolution, and dot pitch (measures the distance between pixels)
What are different units of storage?
Storage: the amount of data or number of characteristics that a device can handle at any given time

Killobyte is 1024 bytes
Megabyte is 1 million bytes
Gigabyte is 1 billion bytes
What's the difference between a bit and a byte?
Binary digits (bits) are numbers, 0s and 1s, that represent data (1 is on, 0 is off)

Byte: a series of eight bits (a byte that represents 0 is 00000000)
What's the difference between volatile and non-volatile memory? What kind of memory is volatile and what kind is not?
Volatile memory: memory that is constantly changing as long as the computer is on and is cleared when the computer is turned off

ex. RAM and CMOS (complementary metal oxide semiconductor... installed on motherboard and is activated during boot process and contains info about where the essential software is opened. Small rechargeable battery powers it. Must be changed every time you add/remove hardware)

Non-volatile: memory never changes and it remains intact when computer is turned off
ex. ROM (read only memory)
-another set of electronic circuits on motherboard
-cannot add to ROM capacity
-When computer is turned on, the set of instructions in ROM checks al the computer's components to make sure they are working, and activates the essential software that controls processing function
What are the two types of files stored on a disk? What's the difference between the two?
Executable files: contains the instructions that tell a computer how to perform a specific task. ex. files that are used during the boot process

Data files: usually created with software
What's the difference between disk storage and RAM? Which is faster? What's the primary purpose of each?
-A storage device receives info from RAM, writes it on the storage medium, and reads and sends back to RAM
-Processor uses RAM to store and retrieve instructions and data s tey are needed

SDRAM (synchronous dynamic)-fast for the average computer and inexpensive

RDRAM (rambus dynamic)-originally created for computer game systems

Hard Disk Drive: speed is measured by access time, time required to read or write one record of data

Optical storage devices: uses laser technology to read and write data on silver platters ex. CDROMS and DVD
What are the components of an information system?
Information system - a group of interdependent elements that transform data into information (ex. Wolverine Access)

Components: Data, people, procedures, hardware, network, software, database, information
What's the difference between data and information?
Data: objective facts and records of transactions

Information: message from data (result of being processed by an information system) to change user's opinion or judgment
What is the purpose of the SDLC (Software Development Lifecycle)?
Isolated functional systems with problematic and inhibited cross-company communication

Integrated enterprise systems such as ERP's (Enterprise Resource Planning) attempt to integrate all departments accross a company onto a single system
What is the involvement of non-IT personnel in the SDLC?
System users: participates in investigation, analysis, review of design, implementation, and approvals

Assurance providers: reviews projects to ensure effective and efficient development processes and that systems developed will be reliable, auditable, and have sufficient controls
What are the three major approaches to application software development?
In-house development
Outsourced development
Software acquisition
When is the appropriate time to use formulas, data tables, PivotTables?
Pivot table: an interactive table that enables you to group and summarize an Excel list into a concise, tabular format for easier reporting and analysis

Data Table: one way of organizing and displaying the results of multiple what-if anaylses
What is a one-variable data table? two-variable?
One-Variable data table
-can specify one input cell and any number of result cells
-particularly useful when one needs to explore how altering one value can impact other values in the workbook

Two-variable data table:
-Uses two input cells but only the value of a single result cell is displayed
-Often used by businesses that need to explore the impact of two values of a single result
-Must always place a reference to the result cell in the upper-left corner of the table at the intersection of the row values and the column values
What is the benefit of using a data table? a PivotTable?
PivotTable:
-easier for reporting and analysis
-Can easily rearrange, hide, and display different category fields int he pivot tables to provide alternative views of the data

Data tables:
-ability to investigate different possibilities (what-if analysis)
-Enables you to quickly see how changing variables (inputs) can affect the value of a calculated figure
The difference between absolute and relative addressing.
Relative addressing:
-the practice of referring to cells to the left, right, up, or down.
-Allows us to copy formula to the cells below and change values for that specific cell

Absolute addressing:
-we want to refer to a specific cell and have that reference never change from cell to cell
-use cell names
How do you do "what-if" analysis with Excel?
On the toolbar click the data tab. Click what if tool. This allows you to use the scenario manager, goal seek, or create a data table. These three things will let you create an analysis to observe what can happen if various aspects are changed.
How do you do sensitivity analysis in Excel?
Sensitivity analysis: is used to analyze which assumption of the model are critical and affect the choice to be made. By using a combination of the options under what if analysis it is possible to gain an understanding of what assumptions have a large impact on the model.

ex. by using a data table, it is possible to paint a clear picture of how certain assumptions such as price and interest rates will have a huge impact on the NPV
How might you use goal seeking?
Goal seeking is used to see what values are needed to be inputted into a model to achieve a specific goal
How might you use scenario analysis?
Scenario analysis can be used when you want to simulate several different situations in a specific model.

ex. how changing interest rates will affect NPV of a product
What is a mathematical model and simulation model?
Mathematical model: a quantitative representation, or approximation, of a real object or system

Simulation Model: a model used to investigate dynamic behavior
ex. if we vary inputs how do outputs change?
Why is model validation important? What are some ways you might do it?
Model validation is the process of checking and going over a proposed model to see if it is the most up to date model for the proposed solution

Do it by:
-having most skilled people working on the problem
-VLookup is a specific tool that is used to consolidate data and make sure the model is working
What is a database? What is its purpose?
Database: a repository of structured business data. Collection of related tables
ex. Customer names, telephone numbers, etc

Contains large volumes of data that many people can access
What is a database management system? What are its components?
Database management system: software that controls the creation, maintenance, and use of the database

Components:
-Data dictionary: tells what fields, records, tables are in a database and their properties
-Data definition language: for defining fields, records, and tables and their relationships
-Data manipulation language: for reading and changing what is in a database
-Database utilities: for things like backing up the database
-Report generator: make sit easy to create reports from a database
What are the benefits of a relational DBMS (Database management system)?
Relational DBMS: data is organized as a collection of tables through a common field....Makes it easier to manage large amounts of data

-Allows you to create database structure containing fields, tables, and table relationships
-Lets you easily add new records, change field values in existing records, and delete
-Contains built-in query language, which lets you obtain immediate answers to the questions you ask about your data
-Protects database security, control, and recovery of files
What is the benefit of relational database over a flat file table? What types of problems are fixed by moving from flat file to relational?
-Flat table: changing one value requires changing the same value in 2 or more locations
-Flat Table is easy to conceptualize but not practical
-The investment to think the database out far outweighs the cost of changing multiple, redundant values
Parts of a relational data tab
Primary Key: a field, or collection of fields, whose values uniquely identify each record in a table

Foreign Key: an index relevant to this table, but from another table tied to this table through a relationship

Attribute: fields or data items

Tuple -Row/Record
What is normalization? What's the purpose?
Normalization: process of ensuring that every field in a table depends on the key, the whole key, and nothing but they key

Eliminates problems in insertion, update, and deletion

Results in a database where:
-facts are stored only once
-easy to relate data in different tables
-can ask ad hoc questions
"Every field depends on the key, the whole key, and nothing but the key."
No fields are dependent on fields other than the primary key
What's the purpose of building an ER (entity relationship) Diagram?
Entity relationship modeling: analogous to preparing architectural drawing before building a house

ER diagram tells you:
-what tables you need in your database
-what primary keys you need
-what foreign keys are necessary
Be able to define entity, attribute, and relationship as used in ER diagrams
Entity: the "noun" -> a collection of things that share common properties or characteristics (ex. Person: employee, student, patient; Place: station, region, country
-Denoted with a rectangular symbol in ER modeling

Attribute->named property or characteristic of an entity of interest to an organization (something that defines the entity) ex. Student number or name
-Denoted with an oval branching off of the entity (rectangle)

Relationship: an association between instances of one or more entity types. ex. the professor TEACHES the course
-Denoted with a triangle connection two rectangles
With what is Codman's triangle associate?
osteosarcoma
Define field, record, table, relational database, primary key, and foreign key.
Field: a single characteristic or attribute of a person, place object, event, or idea

Record: a complete set of field values for a specific person, place etc.

Table: a collection of fields that describe a person place etc.

Database: a collection of related tables stored in the same file

Primary Key: a field whose values uniquely identify each record in a database table

Foreign Key: a primary key field from another table that you include as a field in the second table to form a relationship between the two
Four types of Access objects that might be displayed in the navigation pane?
Tables, reports, forms, queries
What is an access data type?
It is the type of information that you input into a table in access
What is a query?
A question you ask about the data stored in a database; in response, access displays the specific records and fields that answer your question. This allows you to display selected fields and records from a table, sort records, perform calculations, generate data for forms, reports and other queries, update data in the tables in a database and find and display data from two or more tables.
What are two different ways of creating an Access query?
1. Design your own
2. Use the query wizard
What is a form and what can you do with it?
A database object you can create and customize to maintain, view, and print records in a database in different ways
What is a report?
A formatted printout (or screen display) of the contents of one or more tables in a database
What happens when you compact a database?
when a database is compacted, deleted/replace database elements are removed, leaving only active database elements. This makes the database smaller and leaves more room on the disk
Guidelines for designing a database
ER diagram which tells you what tables you have in your database, what primary keys and foreign keys
ex. doing an architectural drawing before building a house

Normalization: the process of ensuring that every field in a table depends on the key, the whole key and nothing but the key... Eliminates problems in inserting, updating, and deleting
-facts are only stored once, easy to relate data in different tables, can ask ad hoc questions
Define entity integrity and null value
Entity integrity: one of the three inherent integrity rules. Entity integrity is an integrity rule which stats that every table must have a primary key and that the column chosen should be unique and not null.

Null value: an unknown or missing value. Unknown piece of data
What is referential integrity?
Referential integrity: in a relational database is consistency between coupled tables. It is usually enforced by the combination of a primary key. Tables aren't allowed to be related sometimes if there is no referential integrity. It will perform an error or delete the foreign key rows.
What is an RSS feed? What does a URL for a RSS feed look like?
A structured document that contains summaries of and pointers to news and blog items. It stands for really simple syndication.

rss.cnn.com/rss/cnn_topstories.rss
What is an RSS reader?
A web-based program that organizes all of a person's RSS subscriptions and displays them
How is an RSS document structured differently than an HTML document? Why?
An RSS document simply has text only. This is so that the information is extremely efficient to load and the reader can simply read the topic instead of having to wait for an image heavy website to load
What are some benefits gained when moving from a RSS reader application based on your own computer to a Web-based RSS reader?
You can network with friends and see what feeds they are reading and add them to yours. Additionally, if you are ever not near your computer you can access it from other computes.
What is the difference between search and discovery?
Search - looking for information about a specific topic

Discovery: finding something that you did not know
What does it mean to participate in a social bookmarking site?
It means when you add websites to your bookmarks, they get put on a website that compiles them based on tags you place on them. You can access them anytime in order to have your bookmarks. You can also look up bookmarks of other people
What are the benefits and drawbacks of social bookmarking?
Benefits: accessible anytime, allows you to organize and access bookmarks

Drawback: you cannot access it unless you have internet access
The meaning and use of HTML tags for links and images.
HTML is hyper text markup language. It is the way the internet is encoded. It's a programming language for websites. You much include html tags when inserting links so that the browser can read, interpret and then properly display the image or link.
What distinguished blogging from normal HTML pages? Is a blog an HTML page? Is an HTML page a blog?
Blogging is frequent, chronological posting of comments. Normal HTML is not as frequently updated and is displayed differently.

Blogging does the HTML programming for you.
What is cloud computing?
A computing model of servers, networks, and applications accessible by means of the internet. Cloud computers provide users with virtual servers.
What is Software as a Service (SaaS)?
The vendor provides the hardware infrastructure, the software product and interacts with the user through a front end port.

Ex. web-based email, database processing, inventory control. The end user can use the service from anywhere
What is a smart phone? What can you do with them that you cannot do with a simply mobile phone?
Mobile phones can access the internet and offer pc-like capabilities
What are some threats posed by the WWW?
Malware ->information theft, financial theft, spyware malware phishing
What are some recent developments in search services? (Intelligence Augmentation)
Answer engines

ex. Wolfram Alpha
What are some examples of how "crowd sourcing" is being used to tap into the knowledge of people on the internet?
Wikipedia
Why are some people concerned about the impact of electronic data gathering and the internet on personal privacy?
They track all that we do in the name of security but studies have shown that it does little to actually prevent crime
How are electronic communication services affecting the actions of dissident political groups around the world?
Easy and low risk to spread propaganda across the internet instantly
Why do some companies zealously guard the details of the software that they do use to do business? In what ways can they protect those details?
It gives them a competitive advantage over the competition. Software patents, contracts, tracking programmers, only allowing them to work at the office, firewalls, anitvirus programs
Virtual worlds - Highly realistic but simulated experiences based on computer animation and related information technologies - are common in games and movies. What are some of the business uses of these? What are some concerns?
Conferencing, education, e-commerce

web addiction, loss of social contact.