What is the Difference Between Similar But Different Things, Terms, and Objects

What is the Difference between Photoshop Cs3, Cs4, Cs5 and Cs6

Adobe Photoshop or simply Photoshop is one of the most widely using graphics software all over the globe that helps us in making and editing of graphics both vector based and pixel based. For making designs of webpages, business cards, greeting cards, movie posters, animated advertisements and cartoons, millions of styles are possible thanks to  this miraculous software.