Any question answered...

http://en.wikipedia.org/wiki/Fender

http://en.wikipedia.org/wiki/Fender_(vehicle)

Possibly no more than the difference between English and American 'English'.

Probably not important unless you are uncomfortable with the creeping Americanisation of your native language?

Almost certainly irrelevant when the real issue is water /mud / shit / roadkill and where it gets to in the course of a ride...

Fender, mudguard. It's not my native language and I work for a US company.

What I wan't are full mudguards (not those detachable things) for my fixed running on 700/25 that look a bit more 60's (but not expensive). I got mounting holes near the front and rear axle. It's an old tour/race bike.