At first glance, the small parts inside a computer may look complicated. The interior of a computer case is not particularly mysterious, though. In the following section some basic parts are introduced and explained so that anyone not familiar with computers can understand what is going on inside a computer.
Picture 8: Inside a computer (source: Gustavb, Wikimedia)
The motherboard is the main board of a computer. It is a thin disk containing CPU, memory, a hard disk and optical drive connectors, expansion cards for controlling video and audio, and connections to the computer's ports (e.g. USB ports). The motherboard connects directly or indirectly to any part of the computer.
RAM (Random Access Memory) is the short-term memory of the system. Whenever a computer performs calculations, it temporarily stores the data in RAM. This short-term memory disappears when the computer is switched off. When working on a document, spreadsheet or any other type of file, it is necessary to save it in order not to lose it. When saving a file, the data is written on the hard disk, which serves as a long-term memory. RAM is measured in megabytes (MB) or gigabytes (GB). The more RAM a computer has, the more things it can do at the same time. If not enough RAM is available, the computer becomes sluggish when several programmes are open. That's why many people add extra RAM to their computers to improve performance.
|1 Byte||1 letter or digit|
|1 Kilobyte (KB) = 1000 Byte||1 page of a book|
|Megabyte (MB): 1 MB = 1000 KB
|Gigabyte (GB): 1 GB = 125 MB = 125000 KB
1 movie in DVD quality
|Terabyte (TB): 1 TB = 125 GB = 125000 MB
Library of Congress, Washington DC, USA
Table 1: Compare volume/size
Software, documents and other files are stored on the hard disk. The hard disk is a long-term memory, which means that the data remains stored even if the computer is switched off or disconnected from the power supply. When a programme is run or a file is opened, the computer copies some of the data from the hard disk to RAM. When a file is saved, the data is copied back to the hard disk. The faster the hard disk, the faster a computer can start and load programmes.
Most computers have expansion slots on the motherboard, allowing the addition of different types of expansion cards. These are sometimes referred to as PCI (Peripheral Component Interconnect) cards. It may not be necessary to add PCI cards because most motherboards have built-in video, sound and network cards.
1. Can you name some hardware parts that are inside a computer?
2. In which hardware part are software programmes installed?
3. What does PCI stand for?