The minimum is the lowest or smallest amount possible or acceptable. If you do the minimum amount of work at your job, you might not get fired — but you definitely won't get promoted.
Minimum is Latin for smallest, so clearly English speakers have done less than the minimum amount of messing with the meaning of this word. Obviously, the opposite is maximum. At minimum, you should know that the word means the smallest limit of something. At most, you should be able to talk about its Latin roots.