ASP.NET Controls

An ASP.net control is a class that executes on the server and renders the content on the browser.

When the TextBox control is rendered to the browser, it renders the following content:

<input name="TextBox1" type="text" id="TextBox1" />

The first part of the control declaration, the asp: prefix, indicates the namespace for the control. All the standard ASP.NET controls are contained in the System.Web.UI.WebControls namespace. The prefix asp: represents this namespace.