All websites have standardized sections like left menu, footer and header. These sections repeat
for all pages in a website. ASP.NET introduces the concept of master pages. Master pages act as a
parent page/template for al the pages in the website. So basically you create a master page and the
other pages in the website refer the master page as templates to put in data. Below figure ‘Master
pages Concept’ shows how a simple website for news channel uses the concept of master pages.
So we have a master page with menu, footer and banner. Then any page with in the website like
the headlines, editor special or special new section pages use the master page template.

Visual studio has made the creation of master pages very simple by introducing the same as
template VS.NET IDE.

The master gets created by file name ‘Master.master’. Below figure gives a complete view of
how the master files interact with the child pages to apply the template. So we have two pages
master and child as shown in figure ‘Master and Child page’. Master page have the ‘master’
attribute rather than the page attribute. Master page consists of ‘contentplaceholder’ which acts as
a place holder for data. So in the below master page we have two place holder’s
‘ContentPlaceHolder1’ and ‘ContentPlaceHolder2’. Just below the master page we have shown
the ASPX page which is using the master page. The attribute ‘MasterPageFile’ points toward the
master page ‘MasterPage.master’. We then use the ‘’ tag to point to the main
master section content place holder. So text ‘This is content in place holder1’ is displayed in
‘ContentPlaceHolder1’ and ‘This is content in place holder2’ is displayed in
‘ContenetPlaceHolder2’.

Below figure ‘Final output of master pages’ shows how the display is.