Virtual Memory can be considered as backup memory. It is the space reserved on physical hard disk to behave as RAM in case of emergency. All computers are said to be multitasking. But actually a computer does only one task at a time. But the process is actually so fast that it appears to be working at multiple tasks at a time.
There are situations when the 8GB RAM is not enough to handle all the processes at a time. At this situation, your computer can say "Back off. Let me finish pending first or unload some previous work". This may lead you to either wait pending process to complete or ending up some processes.
But actually, the RAM selects few of its some less important process, transfers it to the VIRTUAL MEMORY on your hard disk, performs the important task, completes them, backs up the process from virtual memory and works on it.
RAM has very high speed of performance. Accessing (transferring data to and from) virtual memory decreases the speed a lot (some claims degrading of speed a 100 times).
Size of virtual memory can be increased manually. Following are the steps to increase on Windows 7 (Administrator rights are required to perform this action. Do it on your own risk).
- Right click on my computer and goto Properties, or goto control panel, select System and Security, select System.
- Select Advanced System Settings.
- Select Advanced tab, select Settings button in Performance.
- Select Advanced tab and select Change... button under Virtual Memory.
- Select Custom Size radio button and fill up the size boxes as you wish.
- Press OK.
In short, you can say that virtual memory behaves as risk management backup for RAM.