A personal computer (PC) is a multi-purpose computer whose size, capabilities, and price make it feasible for individual use. PCs are intended to be operated directly by an end-user, rather than by a computer expert or technician. Unlike large costly mainframe computers and mid-range servers, which serve their users by handling high-speed data processing and complex calculations, PCs are designed primarily for single users. And unlike most electronic consumer goods, PCs are complex products that combine hardware, software, and services.
A PC typically has a central processing unit (CPU), random access memory (RAM), read-only memory (ROM), one or more disk drives, one or more bus ports for Expansion cards sockets(plug-in connectors that give the PC additional capabilities), and input/output (I/O) devices such as a keyboard, mouse, monitor, floppy disk drive, CD-ROM drive, printer port, and serial ports.
The motherboard is the main printed circuit board in the PC. Most of the other components connect directly or indirectly to the motherboard. The CPU fits into a socket on the motherboard and has corresponding RAM slots. ROM chips usually are integrated into the motherboard circuitry. Disk drives plug into special connectors on the motherboard that have built