How to Buy a personal Computer?

What do you need to know and do before you buy a computer?

1 - Before you buy a computer

You need to know what you are going to do with it in the near future but also what you may use it for at later stages. Computer can be used to write documents, play interactive games online, surf the internet to look for information, study online, shop online, do banking online, watch films on DVDs, listen to music, read e-books, create and run an online business and do many more.

2 - You also need to understand the vocabulary related to computer systems

  • Hardware

    All the physical items such as monitor, printer, CPU, speakers, keyboard,... that comes with a computer system.
  • System Software

    Computer programs (set of instructions) that helps the computer do what it is supposed to do. Examples are Linux, Microsoft windows and Mac OS X.
  • Application Software

    Computer programs (set of instructions) that lets the user do things such as write documents (Microsoft word), surf the web (Mozilla Firefox, Explorer,...), play games and many other applications.
  • RAM

    Acronym for Random Access Memory, writable storage devices where data may be stored and retrieved at high speed. RAMs are very important in the speed of execution of applications. A larger RAM makes your computer faster. There other varieties of RAMs such as DRAMs (dynamic RAM) and SRAMs (static RAM).
  • ROM

    Acronym for Read Only Memory which in general refer to non writable and non erasable storage devices containing data that is not to be altered. However EPROMs are an erasable type of ROMs.
  • Hard Disk

    A large capacity storage device that keeps data even when the computer is switched off. The user uses the hard disk to store text files, audio files, video files, pictures to be used at a later stage.
  • Monitor

    Any electronic system to display output in text or graphic format. There are CRT (Cathod Ray Tube), Plasma and LCD (Liquid Crystal Display) monitors. The last two have flat screens, light weight and consume less power than the CRT type. The CRT monitor, however, is much cheaper than both LCD and Plasma screens.
  • Mouse

    A hand held device that can be moved on a flat surface in order to change the position of the pointer on the screen and click on buttons to cause actions. It can also be used to select text and then perform other actions on the selected text.
  • Printer

    It is used to print text and graphics (color and black and white) on paper.
  • Keyboard

    It comprises a set of keys that are used to type words and give commands to the computer.

3 - You need to understand parameters of computer systems

  • The bit (Binary Digit) is the smallest amount of information a computer can handle. The byte is a set of 8 bits.
  • The clock speed of the CPU is measured in Hertz. 1 Hertz is the number of cycles the CPU goes through per second. However this speed is so high that it is usually measured in Megahertz (MHz) and Gigahertz (GHz) where 1Mhz = 1000,000 Hertz and 1Ghz = 1,000,000,000 Hertz. The clock speed of the CPU is also called frequency.
  • The RAM capacity is measured in Bytes. RAM have high capacities and therefore Megabyte (MB) and Gigabyte (GB) are used to measure the capacity of these memories. 1MB = 1024 x 1024 bytes and 1GB = 1024 x 1024 x 1024 bytes. For graphics and video applications, at least 2 GB are needed. You may also ask if the RAM capacity of the computer in question can be increased and what is the maximum capacity you may be able to add in the future if needed.?
  • If you are buying a portable computer, make sure that the Battery life is enough for your use and applications.
  • A minimum of one year warranty is necessary. Systems with 3 years warranty do exist but cost more.