How to access HTML controls in Server side code c#

This is the simple way of getting or accessing the INPUT HTML controls value in server side coding. This will help you in dynamic programming like create HTML controls at runtime and read their values.
In ASP.NET coding, I don't think it is needed to create or declare only ASP.NET server-side controls for a perticular requirement. Sometimes, to make our page more efficient and faster we can write HTML controls by adding runat="server" to access them on server side code [C#], if they really need it in c# code and use for different purposes.