Use these with care. Even though young people sometimes use them without being gender-specific (eg. a group of young women being addressed as "guys"), it does not make much sense to do this, as Wozitoya and Jura point out. While we use "mate" freely in Australia, it sounds unusual if we use Americanisms, eg. dude, buddy, bub, pal, mac. Conversely, I've never heard an American call his friends "mate". "Chap", "guv" and "squire" are particularly British, though "chap" has an upper-class feel to it. Brits also use "mate", but not as often as Aussies. South Afrikaners like using "cousin", and "bro"/"sis" is used in certain contexts here and there. New Zealanders say "bro" often, but with a particular accent (sounds like "brew"). There's a lot more! The rule: be careful about mixing gender, and do not confuse nationality. ;)

As a woman you should not use these terms although in some parts of Australia, men and women call each other 'mate'. You can say, Hi guys how are you to 2 men if they are your friends.

As a woman you should not use these terms although in some parts of Australia, men and women call each other 'mate'. You can say, Hi guys how are you to 2 men if they are your friends.

These words are used for men. Sorry, you are not within this category. You can't use it anytime.

I think you're asking when is it acceptable to use these terms. Is that correct? Using slang such as "Dude" and "man" are for casual settings amongst friends. You would not say "hey dude" to your boss, but saying it to your friend is acceptable.