An identifer is a symbol used in a Pascal program which consists of letters, numbers and certain special characters, used to indicate a specific variable, constant, object, record, type, procedure or function.
For example, in the following piece of code:
program WittsEnd; const Y = 2; var Plugh: Integer; procedure Xyzzy; begin end; begin Plugh := Y * 2; end.
we can say that
Are all identifiers.