Controls are the building blocks of a graphical user interface (GUI). Some controls you're probably familiar with include buttons, checkboxes, and list boxes. Controls provide a means for a user to indicate a preference, enter data, or make selections. They can also provide infrastructure support in areas such as validation, data manipulation, master pages, and security .
There are four types of web controls (each but the first will be covered in detail in this and subsequent chapters):
The original controls available to any HTML page. These all work in ASP.NET as they work in other web pages. HTML controls will be used where appropriate in this book but will not be discussed in detail. For a good resource on HTML controls, see HTML and XHTML: The Definitive Guide, Fifth Edition, by Chuck Musciano and Bill Kennedy (O'Reilly).
These are based on the original HTML controls but are enhanced to enable server-side processing.
These rich and flexible server-side controls are integrated into the ASP.NET programming model. These controls are rendered to the client as HTML and provide the same functionality as HTML server controls and more.
Controls created by the developer. Chapter 14 discusses user and custom controls.
ASP.NET server controls (sometimes called ASP controls because of the way they are coded in content files) are at the heart of ASP.NET, ...