what is a standard solution? and what is a function of an indicator in a titration?

Answer 1

A standard solution is one which has been standardized; i.e., the concn has been determined and you know the concn with certainty.
An indicator is used in titration procedures to tell the analyst the end point (it "indicates" the end point of the titration).

Answer 2

In simple terms, a standard solution is a solution with a concentration that you know, example is a container labelled 1M, it means the content is a standard solution.

An indicator is used to find when the acid and base are completely neutralized in titration