Virtual memory is a technique used by your computer's operating system to extend the amount of memory that is available to the central processing unit (CPU) at any given time. Your computer has a certain amount of random-access memory (RAM) that it uses to operate. RAM holds the executable code of any software that is currently loaded, the operating system's executable code and the global variables associated with any running software. All of these things can consume your memory quickly if you are using a lot of software at the same time. Virtual memory tricks your operating system into thinking that it has more RAM available to it by using some of your hard drive's space to store data that would normally be stored in your RAM. While this extends the capabilities of your system, it can significantly slow down your computer's performance.
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