but i have no clue what they are for and which one i need.
As you haven't said what you are doing it is a bit difficult to tell you what one you have to use.
At a guess I would say you are making up a kit but that is just a guess.
These are three band resistors, that is three bands give the value and the fourth the tolerance.
They go:- value | value | number of zeros | tolerance.
There are also four band resistors that go:-
value | value | value | number of zeros | tolerance.