Many times you have observed that each search engine gives different results on the same keywords. In SEO terms we call it Search Engines Breakdowns. It depends upon on various factors.

1. Trust on Sites
2. Partner Sites
3. Unique Sites
4. And above all Search Engine Algorithms

Now here in this article we will concentrate on only results obtained by Search Engines. For example when we talk about Google then it shows us informative results. It mostly picks the information from Wikipedia. It also relies on trust factor of the site.

On the other hand Yahoo has different scenarios. Yahoo gets the information from social blogs. That is why it is called Social Engine in many SEO societies. It shows lots of results from ebay. Ebay is the yahoo groups partner. On the other hand it also shows many results from del.icio.us. Yahooanswers is also an other site that it integrate it in its search results.