What is an identifier in variables?

Answer 1

A variable itself ia an identifier.

Any valid lexical token in a program that may be identifier, keyword, function name, or class name are all known as identifiers...

edit:
https://en.m.wikipedia.org/wiki/Identifier_(computer_languages)

Answer 2

https://www.w3schools.com/cpp/cpp_variables_identifiers.asp

Answer 3

identifier == something which identifies as being something..

like if you write
int cpp=10;
here cpp is identifier as its used to identify the value 10 with a name ”cpp” this cpp is an identifier.