If you want lots of information on cheese have a look at http://www.cip.ukcentre.com/cheese4.htm#cottage_ta g
Cheese, after all is processed milk! If you have ever made cheese on toast with 'unprocessed' cheese (Cheddar etc) you will notice that the fat separates and floats to the top. Processing was designed to prevent this. Edam and Gouda are possibly the best known processed cheeses in the UK.