How is right?

Hello, Hiops-- and welcome to English Forums.

Both sentences are grammatically correct and mean that the job is complete.

But I thought that first expression is for expressing, that job is regularly done. And second, that the job is( has been) complete. But I see people use both of them for the second meaning, and the first expression is also used for first meaninig. So why is that? And how to to distinguish this two meanings for the first expression? I hope I did not confuse anybody here, but I'm confused about t

The job is done can mean that it is done regularly only if you include the word regularly or some other information to indicate that:

The job is done regularly,
The job is done by elves.
The job is done Tuesday mornings.

As it stands (The job is done),the only reasonable interpretation is that it has been finished. Done is used here as

Thank your very much Mister Micawber! I asked this question many times from native englishspeaking people here in Canada, but nobody was able to explain that. Now at last I know that, thank you very much again. About which and what is another issuer with me, because when I say 'what' nobody understans me, so I always say 'which' instead of 'what', and when I write I take the revenge on that iss

Which and what as interrogatives are often interchangeable, but not with How. Overall, your English seems to be progressing nicely.

Do you mean that: Which is right, and what is right, would be both correct in my case?

No, which is right is right here, because there are clearly only two options.