This is for a Web Interface used to administer OpenWrt. For running a WebServer see webserver.
You can read about WebGUIs on http://lwn.net/Articles/420066/ from 2010-12-22
Mainly Lua (programming language)
will eventually replace luci
Not to be confused with the c. 2019 X-Wrt which is a close fork of OpenWrt, there was a “webif” called X-Wrt many, many years ago. It's gone.
server-side scripting that is necessary is done using haserl .