Answer 1

A stored procedure does not have to return any data and cannot be used in a Select statement. It will be called or executed and applied a series of actions. This could be a set of queries that is run periodically, e.g. to run optimisation on a set of tables.

Functions must return data and can be used in a Select statement. An example may be SUM() where you provide a set of data and the function returns the sum of the numbers.