Hi, I was reading about hummingbirds and sunbirds and came across this: "sunbirds are the old-world equivalent of the new-world hummingbirds".I'm also aware that these terms are used for monkeys. May I know what does 'old-world' and 'new-world' mean and is it applicable to be used for all animals?
Thanks!

see
http://en.wikipedia.org/wiki/New_World