Linux Memory Management deploys a technique called virtual memory. Virtual memory essentially creates a unified memory device by virtualizing computer hardware architecture such as RAM modules and HDDs. This technique was created to stem the physical limitations of computers as the demand for more memory surpassed consistent progression of hardware improvement in computers. The focus of virtual memory is to act as an extension of computer architecture itself.
Virtual memory is an integral part of an operating system. It gives the illusion that the system has more memory than it actually has by delegating memory between processes as needed. Other advantages of virtual memory are memory allocation, protection, memory mapping and shared virtual memory.