What is the difference between function and procedure in PL/SQL?

Question

What is the difference between function and procedure in PL/SQL ?

Answer 1

1. we can call a stored procedure inside stored Procedure,Function within function ,StoredProcedure within function but we can not call function within stored procedure.
2. we can call function inside select statement.
3. We can return value from function without passing output parameter as a parameter to the stored procedure.

This is what the difference i found. Please let me know if any .