Server Side Controls in ASP.Net
In ASP.Net you have server side controls apart from the ordinary html controls that are used in the web page. The server side controls are executed on the server and they have an attribute runat=server. This attribute that is found in the control indicates that it is a server side control.
The main advantage of using the server side control is that you can separate the code that is executed and the code that is used for display. By using the object oriented programming model of the server side control you can even create complex server side controls. They have rich set of properties, methods, and events.
There are basically three types of server side controls in ASP.Net. They are HTML Server Controls, Web Server Controls, and Validation Server Controls. The html server controls are ordinary html controls with an added attribute runat=server. The web server controls have the syntax,
<tag_prefix:control_name attributes runat="server"/>
validation server controls also have the same syntax and they are used to validate
the input that is given by the user in the forms. With this validation server
controls you can also throw some error message to the user if their input is invalid.