17.1 Introduction
A master page is a template that contains page elements (e.g., text, HTML, ASP.NET server controls) and a content placeholder that reserves space for its associated content pages . Every page element that is placed in a master page (outside of the content placeholder) is displayed on every content page associated with the master page. Thus, when a master page is employed, the master page itself remains consistent from one content page to the next. The only thing that changes is what is displayed in the content pages.
Master pages are useful because they ...
