The Placeholder Web server control enables you to dynamically add server controls to a page at run-time. The Placeholder is an empty container control with no HTML rendering on its own; instead, the control renders any child elements it contains. There are many situations in which it might make sense to add a control dynamically at run-time rather than statically at design-time. A portal application, for instance, may consist of only a few pages, each containing Placeholder controls that are loaded with the appropriate server and user controls at run-time according to some algorithm or some content in a database.