The Token is an identifier. It can be constant, keyword, string literal, etc. A token is the smallest individual unit in a program. C has the following tokens:
Identifiers: Identifiers refer to the name of the variables.
Keywords: Keywords are the predefined words that are explained by the compiler.
Constants: Constants are the fixed values that cannot be changed during the execution of a program.
Operators: An operator is a symbol that performs the particular operation.
Special characters: All the characters except alphabets and digits are treated as special characters.
In general, a token is an object that represents something else, such as another object (either physical or virtual), or an abstract concept
Token, an object (in software or in hardware) which represents the right to perform some operation