Identifiers are the names that are given to the various program elements such as functions, class, variables, list, tuple etc.
They are defined to give a unique name to an entity to identify it during the run time of the program.
There are some rules for making an identifier in python -
Three of them are valid identifiers in python.
The above declaration will raise a syntax error.
In this case pass is a keyword of python language so this is invalid declaration.
The given identifier is invalidand it will raise an error.
Here, i and I both are different and are stored in different memory locations.