What is the role of paging and swapping files in virtual memory management?

Answer 1

Every computer has a limited amount of RAM memory in which to run programs. If you have several programs opens or are using several/large data files, you will run out of RAM. So Windows will set aside space on the hard drive of your computer and use it as additional RAM memory. This is much slower than real RAM memory, so Windows will attempt to move programs you are not currently doing anything in or parts of the data you are not currently accessing into those files. If you attempt to open that part of the data or switch over to the program, it will "swipe" out something else and move that information back into RAM. Thus it is called a "swipe" file. Its purpose is to prevent your computer from running out of RAM anc crashing.

Answer 2

The computer gets to pretend that it has more RAM than it actually does by abusing disk drive(s).
Paging: Some RAM used by less-active processes may be stored temporarily on disk until needed.
Swapping: All the RAM used by a process (including the process's program itself) are stored on disk until the process is needed to do something.

Your computer's operating system determines how transparent that operation is to an application. Versions of Windows prior to Windows 95 had locking and unlocking of handles to memory. A locked handle meant that the desired memory associated with the handle would be in RAM. There were a limited number of such handles available to an application programmer.

Answer 3

Long story short (paging/swapping) files are storage set aside by the OS to act as memory ("virtual" memory) that can be used when you run out of physical memory. Clearly it isn't as fast as physical memory, but it is better than running into "out of memory" errors and your apps being forcibly closed by the OS.