What is a swap space?
It often happens that the computer runs out of RAM. Basically, this means that there is not enough memory in the RAM to hold all the programs that are running at the time. This would normally lead to the slowing down of the computer, and/or cause some programs to crash and stop working.
However, Linux has a word around for that. It is Swap Space. Swap space is a space on a hard disk used can be used to store memory that would normally be held in the RAM. This space actually works as the virtual memory extension of a computer's real memory (RAM).
The benefit of swap space is that it allows the computer to have more RAM than it actually does.