This article will help you understand what is temp table, table variable and the difference between both of them
A computed column is computed from an associate expression that may use alternative columns within the same table. The expression may be a non-computed column name, constant, function, and any combination of those connected by one or a lot of operators however the subquery can’t be used for the computed column.
In this artical,I have describe difference between Primary Key and Unique Key
User Defined Table Types And Table Valued Parameters In MSSQL
Backup SQL Database In SQL Server Management Studio