need basic wifi shield understanding

Hi Im new to both arduino and this forum, anyway im working on a led scoreboard and i want to control it wirelessly.
I have identified the wifi shield as a suitable candidate for the job because there is a reliable wifi connection throughout my school campus.
I have read some posts and article on the device but i am not familiar with some of the technical jargons that were used so all i need i just a basic understanding of how the wifi shield works and how to creat an interface for it.

This is my understanding of the wifi shield :
(1) Create the sketch on the wifi shield and attach it to the arduino

As far as controlling it with a web page i am clueless.

please assist