DVD is an optical disc for storage. It comes in DVD recordable and DVD rewritable formats, which can be recorded, written, burned, whatever you might want to call it, either once or multiple times. Laser is used to write on such formats of such DVDs which is contrast to the mass produced DVD-ROM which is written by pressing. Generally DVD recordable refers to both rewritable as well as to write-once formats. 

As CDs are the predecessor of DVD, so just like CD-Rs, the recordable DVDs are made of plastic and use dyes. Dyes are the reason the data side of the discs has colors. Laser is used to mark sports on the dyes. Infact, the laser burns a spot on the data surface. Hence the name dvd burning, which is commonly used in our everyday life simply as dvd copying.

To copy dvds, you need writeable dvds, dvd writer drive, and a dvd copy software. This software ranges from the very basic to very advanced, catering to all type of end users. Not every software will offer features like video disc creation, data verification, etc. So its an important decision to select the dvd copy software wisely. However with so much advancement in software technology, dvd copy software are becoming cheaper and cheaper with every passing day. But whichever software you use, which ever hardware you have, the discs will be written by burning.