It's the question that drives discussions for decades. Recently I ended up with very interesting article. It's called "The real difference between SQL Server and Oracle".
For years now there's been a constant war between Microsoft supporters and Oracle supporters. Oracle has these features, SQL Server has these features, etc. But that's not really where the real importance lies. Sure, functionality is a part of it because your database should be able to do what you need it to do. However, do you want to know what the real difference between the two companies is and why Microsoft has made such a strong impact in the industry?
You can read the full story here. I hope you also find it interesting :)