What Is The Difference Between Blue Cheese And Gorgonzola?

Actually blue cheese is a general category of cheeses that are made by introducing a bacteria into the cheese so that blue cheese mold forms in veins in the cheese itself.  Gorgonzola is simply an Italian-made blue cheese.  It's made from cow's milk, and is aged for about 4 months.  Other kinds of blue cheese may be made from cow, sheep or goat milk, and aging time may vary, and generally this results in the differences in taste/flavor and pungency.  The kind of blue cheese we often see at the market in the US is akin to Roquefort (made from ewe's milk), with a very pungent, tangy taste and odor.  Gorgonzola is milder in flavor and smell than many blues.

Here is a great article from wiki about blue cheeses:
Blue Cheese

I like both, but I think Gorgonzola is easier to cook with, I do prefer blue cheese with cold items such as salads and dips.