I have created a Module(Portal). I am going to publish it. I just don't know which version it can support. The previous versions and future versions. I am just curious above this all specially in case of .DLLs.
Please suggest me.
Development system
1- Visual Studio 2015
2- DotnetNuke 7
It will all depend on what version of the DotNetNuke.DLLs you compile your module against.
Typically if you compile against a version, say 07.00.01, the module will run on that version AND any NEWER version of DNN.
There are some cases where there are breaking changes for modules on upgrade of the DNN version, but they are pretty few and far between.