1. What are differences between delete and truncate statement ?

Delete is an DML statement.When we delete the data that data can't delete permenently without we give commit command.But Truncate is an DDL statement.When we truncate the data that can be deleted perminently without given commit command also.  

delete is DML and truncate is DDL.

Delete is slow and truncate is faster.

Using Delete we can delete specific records where as truncate cannot.

Delete can be used inside the function or procedures directly but not truncate(only with Dynamic SQL).

Delete is DML command used for delete