Computers

The Different Types of Computer

There are different types of computers and some of the categories are:

Super Computer:  These are the fastest and most expensive computers in the World; sometimes costing over a hundred million pounds to build. They are used by large universities and large organisations and they need to be kept in rooms that have air conditioning and other environmental controls to keep the atmosphere dust free. They also need their own backup electricity generator to ensure that they can continue to work even if there is a power failure

Mainframe Computer:  These are powerful computers that can carry out lots of different tasks for numerous users at the same time.  They can execute billions of instructions per second and process large amounts of data simultaneously. Companies such as Banks; Hospitals; the Police etc use Mainframe computers.  They need to be operated and maintained by specially trained staff.

PC (Personal Computer):  A PC has a CPU (Central Processing Unit) housed in a metal or plastic case. They will also have a keyboard and mouse (used to input data) and a monitor (used to output the data). Modern PCs are powerful and can carry out millions of calculations per second.




Laptop:  Laptops are very popular as people prefer to be able to move around whilst working.  Some people may use a laptop at work and want to go to different buildings/offices and therefore they take the laptop with them and are able to continue to work. In the same way at school we use laptops so that teachers and children can have access to computers where ever they are in the building.  Wireless technology (WiFi) has made this possible.

Notebook:  Is basically a smaller laptop making it easier for the user to transport and carry around.

At one time you could also buy PDAs (personal digital assistants) and Palmtops computers, but as mobile phone technology has advanced our mobile phones can now do more that these devices could do and so they have disappeared.

Embedded Computers: We all use embedded computers everyday without giving it a second thought. An embedded computer is a single chip sometimes these are known as ‘micro controllers’ because they are used to control something. Examples of their use is in telephones, televisions, cameras, washing machines, dishwashers, cars etc

The Parts of Computer

The CPU (Central Processing Unit):  This is the brains of the computer and it does all the calculating. The number of calculations it carries out (or processes) is measured in gigahertz (GHz). The higher the processing speed, the faster the computer.

The Motherboard

The Motherboard: The motherboard is the main circuit board. It is the most 'central' part of a computer. All of the different parts of the computer are connected to the motherboard. This lets them work together.

Memory Cards

Memory:  —This usually refers to RAM (Random Access Memory), which is the temporary memory that the computers uses. Ram is used to run the programs that are open on the computer. The more RAM that you have, the more programs that can be opened at any one time.  If you are using your computer to sophisticated graphics packages or videos you will require more RAM.  —RAM is known as temporary (or volatile) memory, so when the computer is switched off what ever was in the RAM is lost.

HDD (Hard Disk Drive)

Hard Drive - Primary Storage:  —The hard drive is the primary storage area of the computer it is where the software files and data are kept and where they are retrieved from. —The size of the hard drive is measured in bytes – usually GB gigabytes (but today sometimes TB terabytes). The bigger the hard drive, the more data can be stored.

Wireless Enabled (WiFi):  If your computer is wireless enabled it allows the device to pick up WiFi signals, enabling you to connect to a network, connect to other devices and access the Internet without wires.
—Wireless connection is generally slower than data travelling through a cable. This is because data can be distorted as it travels through the air by other signals and interference. This can cause lag in programs.

USB Connection: USB (Universal Serial Bus) is the most common method of connecting devices to a computer.  You might use a USB for a memory stick, or you may use it to connect a keyboard or mouse.

Sound and Graphics Cards: These are devices that fix into the computers main circuit (the motherboard), allowing computers to play and record sound and display graphics. Different cards will enhance the sound and graphics, to be able to 'game' you will need a good graphics card.

Graphics Card

Optical Drive

The Optical Drive:  —The optical drive uses lasers to read data encoded on CDs and DVDs. Optical drives might be used to install software, listen to music or watch films. Some optical drives also allow CDs/DVDs to be written (burned).

For further information have a look at this clip:

You also need to know some of the Ports on a computer and what they are used for:

Connectivity

Devices are able to connect to each other and share data.  There are different ways in which you can connect devices so that they can do this:

Data Cable Connection:  This is the most common way using a USB cable.  Most mobile phones can connect to a computer using a USB cable and running the correct software.

Bluetooth:  Bluetooth allows the devices to communicate with each other wirelessly over short distances.  They use radio waves in order to do this.  Most modern devices are Bluetooth enabled or a Bluetooth dongle can be attached to a computer as a peripheral.

WiFi:  This works in the same way as Bluetooth, but it can work over longer distances.  WiFi allow devices to connect with a computer network and the Internet.  It can also be used to connect to WiFi enabled peripherals such as printers, speakers etc

Synchronising:  When 2 devices, such as a phone and a computer, are connected they can automatically exchange data.  This is known as synchronisation.  This can also occur with devices that use cloud storage, using apps such as iCloud or software such as Dropbox.

Input / Output / Storage

You should also know about the difference between INPUT; OUTPUT and STORAGE devices.

This is quite a basic concept, but one that is still important and that you should understand.

An INPUT device inputs data into the computer.  Examples being the keyboard, a mouse, a scanner, a touch screen, a microphone.

An OUTPUT device outputs data from the computer.  Examples being the monitor, a printer, speakers.

A STORAGE device stores data from the computer.  Examples being a HDD (Hard Disk Drive) a USB Flash drive; an external hard drive.

Ergonomics
An important consideration when you buy new digital equipment is whether you will be able to use it comfortably.  Ergonomics is the the science of designing equipment so that it is comfortable and user-friendly.  Good ergonomic design can help prevent repetitive strain injuries (RSI) and other health problems.