Vista is one of the multitasking operating system and it is possible to have a word processor, a spread sheet and a web browser all open on the Vista desktop at the simultaneously. Every application occupies its own space in system memory. High memory your system has the more applications that can be open at the same time. A CPU can only doing the process one task at a time and all application programming code is stored in memory. To process multiple applications, the processor must be fed code from every program one at a time.
Every application is allotted only a slice of the CPU processing time. When the CPU processes the second program, the operation from the previous program is store to a unique register with in the CPU. The multiple applications appear to be running simultaneously.
Actually, every application is starting and stopping thousands of times a second, and Windows manages the whole operation, so that none of the processes bump into one another. By saving the unprocessed code in this module, the CPU knows correctly where the process was paused and where to resume when it is that programs turn again.
