On March 2nd, 1995 the site that started life as “Jerry’s Guide to the World Wide Web” incorporated as Yahoo (with an exclamation of course). I remember the early days, when all the pages had grey backgrounds and seemed to lack structure. It sure has come a long way. Tony Long at Wired explains:
Originally founded as a search engine/web directory, the company expanded rapidly through acquisitions to diversify into a full-blown internet service company, offering e-mail, instant messaging, social networking, online shopping and news, among other things.
I like Yahoo!, in case you hadn’t noticed, despite their growing pains.
And here’s a cool bit of trivia I just read on Wikipedia: if you click the exclamation point in the Yahoo logo on the homepage, you’ll hear the Yahoo yodel!
Read: Wired
MasterMaq's Blog 
Originally founded as a web directory actually, because I was one of the people at Open Text that built the search engine that Yahoo! first used. We co-announced that partnership on September 22, 1995. All Yahoo! searches went to the Open Text Web Index, which I believe was the first full text search engine for the web.
Larry, you’re right, web directory is more accurate! Must have been pretty neat to be part of such an interesting (and at the time cutting edge) project.