Asp.net User Control Vs Custom Control

Development and Deployment:-

User control:-

• Basically Designed For a single application.
• Deployed in the source form (.ascx) along with the source code of the application.
• If the same control needs to be used in more than one application, it introduces redundancy and maintenance problems.

Custom control:-

• Designed so that it can be used by more than one application.
• Deployed either in the application's Bin directory or in the global assembly cache.
• Distributed easily and without problems associated with redundancy and maintenance.

Design:-
User control:-

• Creation is similar to the way Web Forms pages are created; well-suited for rapid application development (RAD).
• Much better in cases where static contents are more than logic.

Custom control:-

• There is no direct UI availabe at Design time,so lots of code required.
• Better when we have more logic compare to content or we can say when requires dynamic contents to be displayed.