Salary is given per month
But generally we say the package and most of time it refers to the annual ( yearly). Just in saying but we get our salary per month.
So I think you get my point.
Good luck.

Hii

Please mention what salary are you talking about. Generally if you see the salary paid by a company for the employee for his job is per month. But when it comes to official written status, like when you have to fill your income in any form or you check what salary would be paid to you if you apply for some job or post, that time it is written for yearly or in terms of per annum.
So if you can please specify what salary are you talking about, then i can help you better.

Thanks!