Virtual memory is a memory management technique that allows the execution of processes that may not be completely in the main memory (RAM). It creates an illusion for users that there is almost unlimited memory by using both hardware and software to map logical addresses to physical addresses. The operating system divides virtual memory into blocks called pages and transfers data between physical memory and storage as needed.

Virtual Memory is a memory management technique that provides an “idealized abstraction” of the storage resources that are actually available on a given machine, thereby creating the illusion to users of a very large (main) memory. It allows processes to execute even when their memory needs exceed the physical memory available, by swapping data between physical memory and disk storage. Formally, virtual memory is defined as a system that maps virtual addresses to physical addresses using a combination of paging, segmentation, and a page table to manage memory access and optimize resource usage.

This system allows for better utilization of memory, enabling large applications to run even when physical memory is limited. Virtual memory also isolates processes, enhancing security and stability since processes cannot directly access each other’s data. The OS manages virtual memory through techniques such as paging and segmentation.

Despite its benefits, virtual memory has some drawbacks, such as slower performance compared to operations purely in physical memory. Page faults occur when data required by a process is not in RAM, requiring retrieval from slower storage, which introduces latency. Efficient page replacement algorithms like Least Recently Used (LRU) are essential to optimize its performance.