The specification or “spec” is a list of the key components that make up the computer. It is provided by retailers to help buyers decide which PC and which combination of feature they need. When buying a PC it is important to start deciding what you want the PC to do.

When specifying a computer the following are normally quoted:

1.The speed of the processor (MHz – GHz): 

The processor is the brain of the computer and controls most of the work done.

Its speed is related to the number of operations it can perform per second. The higher the value, the faster the PC will perform and the more expensive it generally is. The latest dual core or quad core processors have two or four processors on a single chip and operate more efficiently at lower speeds. 

Intel Inc. and AMD Inc. are the two main processors manufacturers, and both offer a range that balances price and performance. Intel Core I3, I5 and I7 are three brand names to identify different ranges (or families) of processors, their primary difference is based on processing power.

2.The capacity (size) of the memory (MB – GB):

RAM is the main working memory of a computer. The processor uses this memory to run programs and to store temporarily data that need to be processed. The last variant of RAM is DDR4.

Its capacity is measured in gigabytes. A minimum of 2 gigabytes is recommended for 64 bits version of Windows 10. The more RAM a computer has, the more processes and applications it can run.

3.The capacity of storage devices (MB – GB):

The hard drive is the computer’s primary storage area. It stores applications and programs that run on the PC, as well as any work created by users. Its capacity is measured in gigabytes. The larger your hard disk is, the more disk space is available for storing files.

SATA (Serial Advanced Technology Attachment) is a standard bus interface used to connect mass storage devices.

4.The speed of the optical storage devices: 

Optical storage devices allow the information on a compact disc to be read and written to by the PC. Their speed is shown (given) as multiple of the speed of the first device produced. CD-R drives are often sold with three different speed ratings: one speed for write-once operations, one for re-write operations and one for read-only operations. Dual layer DVD are DVDs with two writeable layers, each one with a capacity of nearly 4.7 GB.

5.The display monitor size: 

The monitor is the main output device in a computer system. Its size is measured in inches and is given by the distance between two opposite screen corners (diagonally across the screen surface). The older CRT monitors have been replaced by LCD monitors.

6.The monitor image quality (resolution): 

The monitor’s resolution is given by the number of pixels (picture elements) in each dimension that can be displayed, e.g. 800 x 600 - width x height, or by the graphics standard used e.g. VGA (video graphics array – 640x480), SVGA (super video graphics array – 800x600), Full HD (1920x1080).

7.The graphic card memory size (MB – GB): 

The graphic capability in a computer system can be either integrated or dedicated. “Integrated” means that the graphic functionalities are provided by the CPU (or by an on-board graphic controller on the motherboard) and the RAM is shared with the system’s one, while dedicated graphic cards have their own processing unit (GPU) and RAM. 

8.The operating system:

The operating system is a collection of programs that manages and controls applications and other software, and coordinates the various hardware components to perform tasks requested by the user. The last version of Microsoft’s operating system is Windows 10, but there are many alternatives, mostly based on the Linux kernel (kernel is the central module of an operating system). Operating systems can be either 32-bit or 64-bit.