Million instructions per second. It's a way to measure how fast a computer works.
Mips is a good thing because it means the computer is fast and can do a lot of things quickly.
Examples:
This computer can do 100 mips.
My new computer is faster than my old one because it has more mips.
The mips of this computer is very high.
My computer is so slow, it probably only has 2 mips!
I wish I had a computer with a million mips!
A supercomputer can have billions of mips.