Whats the difference between a Samurai sword and a Katana? I always thought they were one in the same but my buddy argues they are different, well he's not really my buddy, but I know him.

Can legit katana's be bought online? If so, where? I dont want to buy one I just want to have a look - we cant import anything sharp/dangerous into my country. By legit I mean the real thing. I've heard there are many copies of Katanas out there which are of quite bad quality, regardless of how pleasing to the eye they may be.

Iv'e also heard it said that the Katana you buy might be different than someone else based on what thier sensei reccommends. Is this true?
Do different styles of Kenjutsu, Iai etc, require different katanas?
Also, how would a sensei determine what is right for you?

Hope you can help.

__________________
"Life is finite, while knowledge is infinite."
- Zhuang Zi (date unknown).