1) A dvd-r/rw drive can copy files that are not encrypted from a dvd to the hard drive. Likewise a dvd ROM type drive(Read Only) can also copy non encrpyted files from a dvd to the hard drive too.
2) You can buy a dvd recorder even in retail stores that will copy files from one dvd to a new blank dvd disk. Likewise a dvd writer(pc) can also be used by a software to create an image of an existing dvd disk and write the files there to another blank dvd. The drive can also be used to play audio cds as well as dvd disks with movies and video files on them.
3) You are not authorized to duplicate previously copyright protected materials(pc games, dvd movies, softwares, etc.) from a commercially released dvd disk to a blank dvd. And discussion on how to do that is not allowed here. Please read forum rules.