User Controls v/s Custom Controls

User Controls

• Custom, reusable controls created like forms
• Reside in .ascx files
• Can't be added to Visual Studio toolbox
• Used either by dragging and dropping on an .aspx page or by adding manually with "@register" tag
• Created by using existing Webserver and HTML server controls
• The class is derived from System.Web.UI.UserControl class

Custom Control

• Reusable controls
• Developed by a developer or vendor
• Derived from System.Web.UI.Control class for non-visual elements
• Derived from System.Web.UI.WebControl class for visual interface
• Deployed either in Bin directory or in Global Assembly Cache (GAC)