Virtual memory

Virtual Memory is a resource allocation system that is used by computer systems to achieve higher computing efficiency. It allows an operating system to use more memory than is physically available in the system. By using “virtual” address space, the operating system can access more memory than is physically present in the system and also share the existing physical memory between multiple processes.

Functionally, virtual memory is the abstraction of physical memory. It allows programs to run in the same address space as one program and another process. By using virtual memory, the operating system can move pages of memory from RAM to disk when they are needed to store information about a running program. This allows the programs to share resources and memory and for programs to run faster.

Virtual memory is used extensively in modern operating systems such as Windows, Mac, and Linux. When a process or program needs more memory than what is currently available in the system, the operating system will use the virtual memory system to locate the needed memory. The operating system will then take a portion of the available physical memory and swap it for the requested memory from the virtual address space. This increases the amount of memory available to the program.

The advantages of the virtual memory system are numerous. Not only does it improve system performance by decreasing memory contention and allowing applications to access more memory than is physically present, it also reduces system complexity. As applications and processes increasingly rely on memory, the virtual memory system provides an efficient and flexible way to manage memory without requiring the admin to understand the complexities of memory management.

In addition, the system is more secure. By swapping memory pages between physical RAM and the virtual memory, it prevents malicious programs from accessing memory that would be unavailable in physical memory. This makes it an important piece of any security system.

Overall, virtual memory is an important part of any modern operating system. By providing an efficient way to manage and improve system performance, it is an essential part of any computer system.