This is the MIPS instruction sheet. We chatted a little bit out "32-bit" operating systems and "64-bit" operating systems.
MIPS is an old-ish set of instructions, which had 32-bits to lay out instructions. These were simple instructions! Take a look at those, below. Anything look familiar?
If you take a look at the bottom, you can see the different allocation of bits to the information for the computer instructions. For example:
We can see that bits 31-26 are for something called an opcode, 25-21 for rs, etc...
This is one way that computers use binary to represent something!