Multitasking is processing multiple tasks at one time. For example, when you see someone in the car next to you eating a burrito, taking on his cell phone, and trying to drive at the same, that person is multitasking.
Multitasking also refers to the way a computer works. Unlike the phone and burrito juggling driver, a computer's CPU can handle many processes at one time with complete accuracy. However, it will only process the instructions sent to it by the computer's software. Therefore, to make full use of the CPU's capabilities, the software must be able to process more than one task at a time, or multitask.
Early operating systems could run multiple programs at one time, but did not fully support multitasking. Therefore, a single program could consume the computer's entire CPU while performing a certain operation. Basic operating system processes, such as copying files, prevented the user from performing other tasks, such as opening or closing windows. Fortunately, since modern operating systems include full multitasking support, multiple programs can run at the same time without affecting each other. Also, multiple operating system processes can take place simultaneously.
Since multitasking can handle several tasks at once, it also improves the stability of the computer. For example, if one process crashes, it will not affect the other running programs, since the computer handles each process separately. In other words, if you are in the middle of writing a paper in a word processing program and your Web browser unexpectedly quits, you won't lose your work. That's when you can really be thankful for multitasking.