Cold Fusion is a server side scripting language like PHP or ASP. Now I'm not all that familiar with PHP since I work mostly on NT Servers but CF is much better than ASP. Its less technical than ASP, it has more functions than ASP, its easier to learn than ASP. Its true with ASP you can create and add functions and whatnot, but out of the box CF does things better. I really like Cold Fusion. People say it wont be around much because its commercial, which is true, but I'm not my hosting company so I don't really worry about the price, and it's a great language to use.
ps check out a Cold Fusion book by Ben Forta, its a very very comprehensive book, the most comprehensive book I own.