Software Deployment

hi i have some basic questions like if we are working as a application packager when we got an application for packaging what should be the right approach? as per my knowledge do they provide setup.exe or vendor msi? if we got setup.exe how to extract msi from it? and if we got vendor msi what to do with that package? how to check whether the package supports for silent installations and is it mandatory to do silent installations each and every time? i am reading a lot about packaging but not getting one perfect approach in which directions i should move so its more confusing.