How long has nikon and canon been around and which is better?

Yeah the title says it all

They have both been around longer than you have been alive, and neither is better than the other.

Nikon was founded July 25th, 1917.
Canon was founded August 10th, 1937

There's no such thing as "better" when it comes to these two brands.

With these two companies there's no "better" so get past that word.

Both have been around a very long time, and both are very good. It's a matter of personal history or choice as to which brand you go with. Look also at Sony if you are looking at DSLRs - Sony is coming up very fast and is challenging the two leaders with many innovative ideas. I'm a Nikon user.