Smallest individual element of a program is called as Token. Everything you see inside a program is a token.
For example – Suppose an English sentence. “C language is an awesome language. C was developed by Dennis Ritchie at AT&T Bell labs in 1972.”
The above sentence is made of Alphabets (a-z A-Z), Blank spaces, Digits (0-9) and special characters (full stop in our case). These are building blocks or basic elements of our sentence. Similarly there are various basic programming elements that makes any program.
There are five types of tokens.