Version Compatibility in import and export of solution

Hello,

I have not clear idea about the solutions which are exported from Dynamics 365 Online with version  8.0,8.1 and 8.2.Then in which account they can import?

Also I want to know that can I import that solutions developed and exported from online account into on-premises account?And if yes then same confusion as above.

Please help me out from this confusion.

Thank You.