What is called Store Procedure ? ?

[thiruvasagamani]

A stored procedure is a set of SQL commands that has been compiled and stored on the database server.

Once the stored procedure has been "stored", client applications can execute the stored procedure over and over again without sending it to the database server again and without compiling it again.

Stored procedures improve performance by reducing network traffic and CPU load.

[karthikn]

i need one example for stored procedure 

and i have aone more doubt

Can u tell the difference between the Stored Procedure and Function     ?