A: Thomas Paine believed that the American army would become the strongest in the world, that America would achieve independence from Britain with a strong ar... Full Answer > Filed Under:
How DVDs Work. DVDs are of the same diameter and thickness as CDs, and they are made using some of the same materials and manufacturing methods. Like a CD, the data on a DVD is encoded in the form of small pits and bumps in the track of the disc. A DVD is composed of several layers of plastic, totaling about 1.2 millimeters thick. Each layer is created by injection molding polycarbonate plastic.
However, these two words actually mean different things. CDs and DVDs are made with a different purpose in mind. Compact Disc (CD) is an optical disc that is used to store data. These are actually made to replace floppy disks that were used to store files and programs from the computer. The CDs eventually caused the floppy disks to become obsolete.