The term p ersonal c omputer properly refers to any desktop, laptop, or notebook computer system. This latter use is similar to what is meant by a WinTel system. If something is portable it can be easily moved from one type of computer to another. A printer is a piece of hardware that will print computer information onto paper. This is distinct from multitasking.
Advertisers often use megahertz numbers as a means of showing a processor's speed.
A program is a series of instructions for a computer, telling it what to do or how to behave. It is however different from an applet. Program is also the verb that means to create a program, and a programmer is one who programs. Loosely speaking, parallel implies a situation where multiple things can be done simultaneously, like having multiple check-out lines each serving people all at once. Parallel connections are by their nature more expensive than serial ones, but usually faster.