Searching the internet was not easy in it's early days. You would basically have to type in the the exact words that you were looking for in order to get a decent search. Two Stanford students saw this problem and decided to act upon it even though they didn't mean for it to become so popular. David Filo and Jerry Yang were two students at Stanford that were part of a fantasy basketball league, but getting statistics for the games was a very difficult task for them, so they developed a search engine that would do the task for them. Later on they name the search engine Yahoo and made billions of it.
Yahoo had become very popular and was being used by a large audience, but it was not making money for David and Jerry. To overcome this obstacle Yahoo started to advertise. Big companies took notice of this and decided to put their add on Yahoo, this would become the primary source of income for Yahoo and its creators. The site Yahoo was popular, but the search results that it produced were not the best. Two other students at Stanford took notice of this and created Yahoo's most dangerous competitor, Google.com.
Ironically Yahoo's downfall would start from the very same college that it was created at. Two student at Stanford University Larry Page and Sergey Brin started their very own search engine name Google, which was a play on the number Googol which is 10 with a 100 zeros after it. Their search engine worked a little differently, instead of popping up any search results for a given term, it would display the most relevant and visited sites. The ranking of a site was based on how many vists it got along with how many times it was referenced or linked in other websites.
Google though had also run into a similar problem as Yahoo, where it aws not generating enough money to keep the site running. Larry Page and Sergey Brin found a smaller company called Overture who was making money selling keywords to companies. Google decided to copy the idea and created something called Google Adwords, Overture sued Google for copying their idea, but the law suit never amounted to anything though. Google had found their financial salvation in key words, which would make them billions on billions of dollars in the future.