Does just what it says on the box. It adds an option to search the AZlyrics.com website to the Firefox search box. It's very convenient that I no longer have to type in "+azlyrics" every time I look up a song. As AZlyrics seems to be the last place left on the internet to look up lyrics without 59GB worth of spam and slow-loading autoplay stuff inundating you. Great website, great addon, five stars and a hearty thank you to the developer(s)!