Igcse Ict Theory Flashcards

Front 1

What is a system?

Back 1

Input->Process->Output

Front 2

What is Hardware?

Back 2

Hardware is the physical parts of the computer system – the parts that you can touch and see.

Front 3

What is Software?

Back 3

Software is a collection of instructions that can be ‘run’ on a computer. These instructions tell the computer hardware what to do.

Front 4

The Difference Between Hardware and Software

Back 4

For a computer to function, it needs both Hardware and Software, as software tells the computer hardware what to do.

Front 5

Some examples of Main Computer Components

Back 5

The:

-CPU

-Main Memory (RAM, ROM)

-Peripheral Devices (Input and Output Devices)

-The Motherboard

-Hard Disk Drive

Front 6

What is an Operating System?

Back 6

An operating system is the most important software that runs on a computer. It manages the computer's memory, processes, and all of its software and hardware.

Front 7

What is a GUI?

Back 7

A GUI is an interface built around visual (graphical) things:

-Windows

-Icons

-Menus

-Pointers

Front 8

Types of Computer?

Back 8

-A Mainframe Computer

-Personal Computer Computer (PC)

-Laptop Computer

-Palmtop Computer

-Personal Digital Assistant (PDA)

Front 9

Mainframe Computers

Back 9

A mainframe computer is a large computer, often used by large businesses, in government offices, or by universities and are often:

-Powerful

-Large

-Multi-User

Front 10

Personal Computers (PC)

Back 10

A typical PC contained the same basic components as a mainframe computer (CPU, RAM, storage, etc.) but at a fraction of the size and cost.

Front 11

Laptop Computer

Back 11

A 'laptop' computer is a light, compact and portable PC which contain a rechargeable battery and a built-in LCD monitor.

Front 12

Palmtop Computer

Back 12

A Palmtop Computer is similar to a Laptop but much Smaller. However they are not as powerful as fast CPUs require a large battery and get hot. They also have a small keyboard and usually have a tiny joystick or touchscreen.

Front 13

Personal Digital Assistant (PDA)

Back 13

A PDA is similar to a palmtop computer, except it is even more compact, and typically has no keyboard, using a touchscreen for all data input. Since the screen is so small, many PDAs have a small stylus (plastic stick) that is used to press things on the screen.

Front 14

What is an Input Device?

Back 14

An input device is a hardware or peripheral device used to send data to a computer

Front 15

What is an Output Device?

Back 15

An Output device is a hardware or peripheral device used to take data away from the computer

Front 16

Examples of Input Devices

Back 16

Examples of Input Devices are:

-Keyboards

-Sensors

-Mouse

-Scanner

-Microphone

-Touch Screen

-Graphics Tablet

Front 17

Examples of Output Devices

Back 17

Examples of Output Devices are:

-Monitors

-Printers

-Plotters

-Speakers

-Projectors

-Buzzers

Front 18

What are Secondary Storage Devices?

Back 18

An external hard drive is a common secondary storage device used for data backup

Front 19

Examples of Secondary Storage Devices

Back 19

Examples of Secondary Storage Devices:

-Floppy Disc

-CD-ROM

-DVD

-USB Memory Stick

-Backup Tape

-Hard Drive

Front 20

Size order from Smallest to Largest (1-6)

Back 20

1) Floppy Disc: 1.44MB

2) CD-ROM: 800MB

3) DVD: 4.7GB

4) USB Memory Stick: 16GB

5)Backup Tape: 800GB

6)Hard Drive: 1TB

Front 21

What is Random Access Memory (RAM)?

Back 21

RAM is a fast temporary type of memory in which programs, applications and data are volatile, which means, when the power is switched off, all the data is gone

Front 22

What is Read Only Memory (ROM)?

Back 22

The software checks the computer’s hardware and then loads the operating system. It is non volatile, the data it contains is never lost.

Front 23

What is a Network?

Back 23

A network is two or more computers, or other electronic devices,connected together so that they can exchange data.

Front 24

Using a computer connected to a network allows us to…

Back 24

- Easily share files and data

-Share resources such as printers and Internet connections

-Communicate with other network users (e-mail, instant messaging, video-conferencing, etc.)

-Store data centrally (using a file server) for ease of access and back-up

Front 25

Using a computer connected to a network means that…

Back 25

-The computer is vulnerable to hackers

-If the network breaks, many tasks become very difficult

-Your computer can more easily be attacked by a virus

Front 26

What is a LAN (Local Area Network)?

Back 26

A Local Area Network is a network confined to one building or site. Often a LAN is a private network belonging to an organisation or business. Because LANs are geographically small, they usually use cables or low-power radio (wireless) for the connections.

Front 27

What is a WLAN (Wireless Local Area Network) ?

Back 27

A wireless LAN (WLAN) is a LAN that uses radio signals (WiFi) to connect computers instead of cables.

At the centre of the WLAN is a wireless switch or router - a small box with one or two antennas sticking out the back - used for sending and receiving data to the computers

Front 28

What is a WAN (Wide Area Network) ?

Back 28

A Wide Area Network is a network that extends over a large area.

A WAN is often created by joining several LANs together, such as when a business that has offices in different countries links the office LANs together.

Front 29

Examples of LAN Topologies

Back 29

-Ring Network

-Bus Network

-Star Network

-Hybrid Network

Front 30

Examples of Network Hardware

Back 30

-Network Interface Card (NIC)

-Hub

-Switch

-Router

-Proxy Server

-Bridge

-Firewall

Front 31

What is a Hub?

Back 31

A hub is typically the least expensive, least intelligent, and least complicated of the three. Its job is very simple – anything that comes in one port is sent out to the others.

Front 32

What is a Switch?

Back 32

A switch does essentially what a hub does, but more efficiently. By paying attention to the traffic that comes across it, it can “learn” where particular addresses are.

Front 33

What is a Router?

Back 33

A router is the smartest and most complicated of the bunch. A simple way to think of a router is as a computer that can be programmed to understand and route the data that it’s being asked to handle.A router operates exactly like a switch, learning the location of the computers on its connections and routing traffic only to those computers.

Front 34

What is a Proxy Server?

Back 34

A proxy server is a computer setup to share a resource, usually an Internet connection.Other computers can request a web page via the proxy server. The proxy server will then get the page using its Internet connection, and pass it back to the computer who asked for it

Front 35

What is a Bridge?

Back 35

A bridge is a network device that typically links together two different parts of a LAN.Whereas a router is usually used to link a LAN to a WAN (such as the Internet), a bridge links independent parts of a LAN so that they act as a single LAN.

Front 36

What is a Firewall?

Back 36

A firewall is a device, or a piece of software that is placed between your computer and the rest of the network.

A firewall blocks unauthorized connections being made to your computer or LAN. Normal data is allowed through the firewall (e.g. e-mails or web pages) but all other data is blocked

Front 37

What is a Modem?

Back 37

A modem contains a DAC and an ADC.

The DAC allows a digital computer to send data down an analogue telephone line. It converts digital data to analogue data that a telephone line can read.

The ADC does the opposite of a DAC, it converts the analogue signals to Digital data

Front 38

What is the Internet?

Back 38

The Internet is a Wide Area Network of computers and itself, contains many intranets. The Internet is open for all, and the number of users who use the internet is unlimited.

Front 39

What is the Intranet?

Back 39

Intranet is also a network of computers designed for a specific group of users, however the number of users is limited, and traffic allowed is also limited. It is a private network, and businesses and other organisations often have intranets for use by their employees

Front 40

Types of Data

Back 40

-Integers

-Real Numbers

-Currency

-Percentage

-Alphanumeric

-Date and Time

-Boolean

Front 41

Integers

Back 41

An integer is a whole number - it has no decimal or fractional parts. Integers can be either positive or negative

Front 42

Real Numbers

Back 42

Any number that you could place on a number line is a real number. Real numbers include whole numbers (integers) and numbers with decimal/fractional parts. Real numbers can be positive or negative

Front 43

Currrency

Back 43

Currency refers to real numbers that are formatted in a specific way. Usually currency is shown with a currency symbol and (usually) two decimal places

Front 44

Percentage

Back 44

Percentage refers to fractional real numbers that are formatted in a specific way - out of 100, with a percent symbol

Front 45

Alphanumeric

Back 45

Alphanumeric (often simply called 'text') data refers to data made up of letters (alphabet) and numbers (numeric). Usually symbols($%^+@, etc.) and spaces are also allowed

Front 46

Date and Time Data

Back 46

Date (and time) data is usually formatted in a specific way. The format depends upon the setup of the computer, the software in use and the user’s preferences

Front 47

Boolean (Logical) Data

Back 47

Boolean data is sometimes called 'logical' data (or in some software, 'yes/no' data). Boolean data can only have two values: TRUE orFALSE

Front 48

Flat-File Databases

Back 48

A 'flat-file' database is one that only contains a single table of data

Front 49

Relational Databases

Back 49

A 'relational' database is one that contains two or more tables of data, connected by links called relationships

Front 50

Analogue Signals

Back 50

The sound waves that your mouth produces when you speak are analogue - the waves vary in a smooth way. These waves can be converted into an electrical signal by a microphone. This electrical signal is also analogue

Front 51

Digital Data

Back 51

Computers (and most other modern electronic devices such as cameras, mobile phones, etc.) are ‘digital’ devices because they process data in the form of numbers (digits)