ip http server Command

Router(config)#ip http server	Enables the HTTP server, includ-ing the Cisco web browser user interface
Router(config-if)#no ip http server	Disables the HTTP server

Caution:

The HTTP server was introduced in Cisco IOS Software Release 11.0 to extend router management to the web. You have limited management capabilities to your router through a web browser if the ip http server command is turned on.

Do not turn on the ip http server command unless you plan on using the browser interface for the router. Having it on creates a potential security hole, because another port is open.