How to download a file from server using asp.net C#

Downloading a file from server is a common task for most of the applications. Such as client wants to offer free download, free newletter etc. And i am sure that when you read this post you will get another articles with source code download facility. Am i right? Which means its our common task. Here i will try to show you how we can write the code to download a server file into our client or