User controls allow you to save a part of an existing
ASP.NE
T page and reuse it in many other ASP.NET pages. A user control is almost identical to a normal
.aspx
page, with two differences: the user control has the .ascx extension rather than
.aspx
, and it may not have
<HTML>, <Body>, or <Form>
tags.
Reference Link :-
OREILLy-[Custom and User Controls][
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