The Internet

Front 1

E-mail (Simple Mail Transport Protocol or SMTP)
Protocal used on the Internet

Back 1

Distributes electronic messages and files to one or more electronic mailboxes

Front 2

Telnet (Telnet Protocol)
Protocal used ont he Internet

Back 2

Facilitates login to a computer host to execute commands

Front 3

FTP (File Transfer Protocol)
Protocal used on the Internet

Back 3

Transfers text or binary files between an FTP server and client

Front 4

Usenet (Network News Transfer Protocol or NNTP)

Back 4

Distributes Usenet news articles derived from topical discussions on newsgroups

Front 5

HTTP (HyperText Transfer Protocol)

Back 5

Transmits hyptertext over networks. This is the protocol of the Web.

Front 6

Access to Web pages may be accomplished by:

Back 6

Entering an Internet address and retrieving a page directly
Browsing through pages and selecting links to move from one page to another
Searching through subject directories linked to organized collections of Web pages
Entering a search statement at a search engine to retrieve pages on the topic of your choice

Front 7

URL

Back 7

Uniform Resource Locator

Front 8

How are URLs are translated

Back 8

They are translated into numeric addresses using the Domain Name System (DNS).

Front 9

What is the DNS (Domain name server)

Back 9

The DNS is a worldwide system of servers that stores location pointers to Web sites.

Front 10

What is the numeric address of the DNS

Back 10

The numeric address, called the IP (Internet Protocol) address, is actually the "real" URL.

Front 11

What is the format of a URL:

Back 11

protocol://host/path/filename
http://www.house.gov/house/2004_House_Calendar.html

Front 12

Structure of this URL:

Back 12

http://www.house.gov/house/2004_House_Calendar.html

Protocol: http
Host computer name: www
Second-level domain name: house
Top-level domain name: gov
Directory name: house
File name: 2004_House_Calendar_html

Front 13

Several top-level domains (TLDs) are common in the United States:

Back 13

com commercial enterprise
edu educational institution
gov U.S. government entity
mil U.S. military entity
net network access provder
org usually nonprofit organizations

Front 14

What is a Web browser

Back 14

A browser is a software program that allows users to access and navigate the World Wide Web.

Front 15

There are two types of WEB Browser:

Back 15

1. Graphical: Text, images, audio, and video are retrievable through a graphical software program such as Internet Explorer, Firefox and Netscape.

2.Text: Lynx is a browser that provides access to the Web in text-only mode. Navigation is accomplished by highlighting emphasized words in the screen with the arrow up and down keys, and then pressing the forward arrow (or Enter) key to follow the link.

Front 16

What is a Plug-in

Back 16

Plug ins are programs to handle sound, image or video file, handed by a browser to run or display the file. Working in conjunction with plug-ins, browsers can offer a seamless multimedia experience. Many plug-ins are available for free.

Front 17

What are file formats that requiring plug-ins

Back 17

MIME types. MIME stands for Multimedia Internet Mail Extension, and was originally developed to help e-mail software handle a variety of binary (non-ASCII) file attachments. The use of MIME has expanded to the Web. For example, the basic MIME type handled by Web browsers is text/html associated with the file extention .html.

Front 18

ActiveX

Back 18

ActiveX is a technology developed by Microsoft which make plug-ins less neccesary. ActiveX offers the opportunity to embed animated objects, data, and computer code on Web pages. A Web browser supporting ActiveX can render most items encountered on a Web page. As just one example, Active X allows you to view and edit PowerPoint presentations directly within your Web browser. ActiveX works best with Microsoft's Internet Explorer.

Front 19

What is a computer?

Back 19

A computer is an electronic device that executes the instructions in a program.

A computer has four functions:

a. accepts data Input
The Information Processing Cycle

b. processes data Processing
c. produces output Output
d. stores results Storage

Front 20

Hardware

Back 20

the physical parts of the computer.

Front 21

Software

Back 21

the programs (instructions) that tell the computer what to do

Front 22

Data

Back 22

individual facts like first name, price, quantity ordered

Front 23

Information

Back 23

data which has been massaged into a useful form, like a complete mailing address

Front 24

Default

Back 24

the original settings; what will happen if you don't change anything

Front 25

What makes a computer powerful?

Back 25

Speed = A computer can do billions of actions per second.
Reliability = Failures are usually due to human error, one way or another. (Blush for us all!)
Storage = A computer can keep huge amounts of data.

Front 26

Types of Input

Back 26

Data is the raw facts given to the computer.

Programs are the sets of instructions that direct the computer.

Commands are special codes or key words that the user inputs to perform a task, like RUN "ACCOUNTS". These can be selected from a menu of commands like "Open" on the File menu. They may also be chosen by clicking on a command button.

User response is the user's answer to the computer's question, such as choosing OK, YES, or NO or by typing in text, for example the name of a file.

Front 27

What is Processing?

Back 27

Processing is the thinking that the computer does - the calculations, comparisons, and decisions.

Front 28

What is output

Back 28

Output is data that has been processed into useful form, now called Information.

Front 29

Types of Output

Back 29

Hard copy:
printed on paper or other permanent media


Soft copy:
displayed on screen or by other non-permanent means

Front 30

Categories of output

Back 30

Text documents including reports, letters, etc. Graphics
charts, graphs, pictures Multimedia
combination of text, graphics, video, audio

Front 31

Main Memory = Primary Storage

Back 31

Main memory keeps track of what is currently being processed. It's volatile, meaning that turning the power off erases all of the data.

Front 32

What is stored in main or primary memory

Back 32

Main memory keeps track of what is currently being processed. It's volatile, meaning that turning the power off erases all of the data.

Front 33

What type of memory does main or primanry memory use.

Back 33

computers use RAM, or Random Access Memory. These memory chips are the fastest, but most expensive, type of storage.

Front 34

Auxiliary Storage = Secondary Storage

Back 34

Auxiliary storage holds what is not currently being processed. This is the stuff that is "filed away", but is ready to be pulled out when needed.

It is nonvolatile, meaning that turning the power off does not erase it.

Auxiliary Storage is used for:

Input - data and programs
Output - saving the results of processing

Front 35

Depending on the context, for computer communications you might use the terms:

Back 35

Data Communications for transmission of data and information over a communications channel

Telecommunications for any long-distance communications, especially television

Teleprocessing for accessing computer files located elsewhere

Front 36

A communications channel

Back 36

also called a communications line or link, is the path that the data follows as it is transmitted from one computer to another.

A variety of transmission methods used: telephone lines, satellite links, microwave relay.

Front 37

Transmission media

Back 37

means the physical materials that are used to transmit data between computers.

Front 38

Cable
For communications between computers that are linked by cable, there are three choices.

Back 38

Twisted wire (phone line) Advantage: Easy to string
Cheap
Disadvantage: Subject to interference = static and garble

Coaxial cable (round insulated wire) Advantage: Not susceptible to interference
Transmits faster
Disadvantage: Heavy & bulky
Needs booster over distance

Fiber optic line (glass fibers) Advantage: Smaller
Lighter
Faster (speed of light!)
No interference
Disadvantage: Expensive
Harder to install and modify

Front 39

Broadcast - For longer distances or when cables are not practical use:

Back 39

Wireless (infrared, light, radio)
Advantage: Flexible
Portable
Disadvantage: Slower data transfer than hard-wired methods
Subject to interference

Microwave

Advantage: Speed of light
Uses a few sites
Disadvantage: Line-of-sight only

Satellite

Advantage: Always in sight
Disadvantage: Expensive uplink and downlink facilities

Front 40

Two types of signals are used for data transmission:

Back 40

Digital and Analog.

A digital signal is a stream of 0's and 1's. So this type is particularly appropriate for computers to use.
An analog signal uses variations (modulations) in a signal to convey information. It is particularly useful for wave data like sound waves. Analog signals are what your normal phone line and sound speakers use.

Front 41

Modems

Back 41

A modem is a device that translate the analog phone line and the digital computer.

It modulates a digital signal from the computer into an analog one to send data out over the phone line. Then for an incoming signal it demodulates the analog signal into a digital one.

The word modem comes from Modulate/Demodulate, which is what a modem does.

Front 42

Throughput

Back 42

the term for the entire process - how much data is moved during a certain amount of time. Since the modem is only part of the process of moving data, getting a faster modem may not speed up your data transfers.

Front 43

There are two different parts of the data transfer to measure: the digital process and the analog process.

Back 43

Digital
The rate of digital transmission is measured in bits per second (bps). Common rates for regular modems are 28.8 Kbps, 33.6 Kbps, and 56 Kbps where the K stands for thousand.

Analog
The analog side is measured in baud where 1 baud is one change in the signal per second.

Front 44

Physical types
There are three physical types of modems:

Back 44

External
which plugs into a serial port on the back of the computer
Advantages: Can be moved to a different computer easily.
Does not take up a slot inside the computer.
Lights on front are visible to show what the modem is doing.
Disadvantages: Takes up deskspace.
Adds more cables to the tangle.

Internal
where the phone line plugs directly into card through the back of the computer
Advantages: Saves deskspace.
Saves a cable.
Disadvantages: Requires an internal peripheral slot. (They get filled up.)
Must use software display to see the lights that show what the modem is doing.

Acoustical
where the telephone handset is placed into the device, which is connected to the computer (Old technology! Not many of these around any more.)
Advantages: Can use a phone without having to move the phone wire.
Disadvantages: Bulky.
Connection much more prone to static and interference.
Only a standard handset will fit.

Front 45

Types of Digital Modems

Back 45

ISDN modem

Cable modem

ADSL

Front 46

ISDN Modem

Back 46

ISDN modem
(Integrated Services Digital Network) - a digital device using a digital phone line. It actually should be called a terminal adapter, but the name modem has stuck. An ISDN device is capable of higher rates than an normal modem, 64 Kbps for a single line and 128 Kbps for a bonded dual line. ISDN adapters cost more than normal modems and also require special arrangements with the phone company (and more $$ for them, of course!). Fiber optic line is best for the highest ISDN transmission rate, but the copper wires used in most homes and offices will work also.

Note: To get the highest speeds out of your ISDN modem, you'll need a high speed I/O (input/output) card in the computer to which to connect the modem.

Front 47

Cable Modem

Back 47

Cable modem
Hooks up to your cable TV line and can receive up to 1.5 Mbps. You must have cable TV service with a cable company that also provides data service. You will need a special cable box to which you connect your TV and your computer. You will be sharing the line with all of the cable customers hooked up to your particular cable line. The actual transfer rate you get will depend on how many people are using the cable at the same time. Once cable modems become popular in your neighborhood, your speed will slow down noticeably. It will probably still be faster than ISDN.

Front 48

ADSL

Back 48

ADSL
(Asymmetric Digital Subscriber Line) - a new technology that allows a single regular telephone line to serve for normal phone calls and digital data at the same time. An ADSL modem receives data at rates ranging from 384 Kbps to 8Mbps, depending on the particular kind of service. Even the slowest type is 4 times faster than the best ISDN! Besides great speed, ADSL does not require a separate phone line and you are connected all of the time. No more dialing up!

You can use a regular phone on the same line and at the same time that you are surfing the Internet. No more busy signals to your friends and relatives! Another plus is that you can easily hook up all of the new parts yourself. This saves a LOT of aggravation since you won't have to wait on the phone company or the cable TV guy to show up.