One term you might have heard in relation to disks and partitions, is swap space.
Before we talk about swap space,
let's talk about the concept of virtual memory.
Virtual memory is how our OS provides the physical memory
available in our computer (like RAM) to the applications that run on the computer.
It does this by creating a mapping,
a virtual to physical addresses.
This makes life easier for the program,
which needs to access memory since it doesn't have to worry
about what portions of memory other programs might be using.
It also doesn't have to keep track of where the data it's using is located in RAM.
Virtual memory also gives us the ability for
our computer to use more memory than we physically have installed.
To do this, it dedicates an area of the hard drive to use
a storage base for blocks of data called pages.
When a particular page of data isn't being used by an application, it gets evicted.
Which means it gets copied out of memory onto the hard drive.
This is because accessing data on RAM is fast,
much faster than the hard drive where space is at a premium.
Because of this, the operating system wants to
keep the most commonly accessed data pages in RAM.
It then puts stuff that hasn't been used in a while on the disk.
This way, if a program needs a page that's not accessed a lot,
the operating system can still get to it.
But it has to read it from the comparatively slow hard drive and put it back into memory.
Almost all operating systems use some kind of
virtual memory management scheme and paging mechanism.
So how does it work on windows?
The Windows OS uses a program called The Memory manager to handle virtual memory.
Its job is to take care of that mapping of virtual to
physical memory for our programs and to manage paging.
In Windows, pages saved to disk are stored in
a special hidden file on the root partition of a volume called page file dot sis.
Windows automatically creates page files and it uses
the memory manager to copy pages of memory to be read as needed.
The operating system does a pretty good job of managing the page file automatically.
Even so, windows provides a way to modify the size,
number and location of paging files through
a control panel applet called System Properties.
You can get to the system properties applet by opening up the control panel.