Baudot is an encoding standard used for representing characters as binary strings of 5 bits each.
It's used primarily for TTYs.
Although 5 bit strings can only represent 32 different values, it can represent more than 32 different characters since it uses one of its 32 values each to switch between numbers and letters. So, when once it's in numbers mode, all the character values represent numbers, until one of the values tells it that the following characters will be letters. After that all the characters are treated as letters until one of the codes switches back to numbers.
ASCII is a similar coding scheme that represents English letters, numbers and symbols with 7 bit strings (allowing 128 different characters without using mode switching like Baudot does.
ASCII is used primarily in computer text storage and transmission.