Virtual memory is generally used to increase the apparent size of physical memory.

Explanation:
Virtual memory is a memory management technique that allows a computer to compensate for physical memory limitations by temporarily transferring data from RAM (Random Access Memory) to disk storage. It creates an illusion of having more memory than the physical RAM available.

How does virtual memory work?
When a computer runs out of physical memory, virtual memory is used to store data that is not currently being used. The operating system divides the virtual memory space into fixed-sized blocks called pages. These pages are stored on the hard disk in a special file called the page file or swap file.

When a program needs to access data that is not present in physical memory, a page fault occurs. The operating system then retrieves the required page from the page file and places it into a free page in physical memory. This process is known as paging.

Advantages of virtual memory:
- Increased memory capacity: Virtual memory allows programs to use more memory than is physically available. This allows for the execution of larger programs and multiple programs simultaneously.
- Protection and isolation: Virtual memory provides memory protection, ensuring that each program has its own isolated memory space. This prevents one program from accessing or modifying the memory of another program.
- Simplified memory management: Virtual memory simplifies memory management for both the operating system and the applications. It provides a uniform memory model, allowing programs to be loaded and executed regardless of their size or memory requirements.

Conclusion:
Virtual memory is a crucial component of modern operating systems. It allows computers to effectively utilize limited physical memory resources and provides a convenient memory management mechanism. By using virtual memory, the apparent size of physical memory can be increased, enabling the smooth execution of various programs and tasks.