When it comes to storing your software applications, you want the best. You don't settle for anything less than a disc that can store 4.38 GB of data and is read-only. You want a versatile disc, meaning you can use it for various purposes. A Digital Versatile Disc-Read Only Memory (DVD-ROM) does this by storing large software applications, so you don't have to worry about whether or not it will meet your needs and lastly, you want a read-only disc, so no one can accidentally modify or delete any of your precious data. When a DVD is inserted into the DVD-ROM drive, the disc will automatically start up and load a software program or operating system specified on the disc. Often the disc will load a simple disc menu that allows you to select the desired software program or operating system to load. Once the operating system is loaded, you generally cannot change it. You may be able to change the software program or operating system loaded on the disc. Once the desired software program or operating system is loaded, you can save data files to the DVD-ROM disc. These data files have the same properties as a DVD-ROM disc. They cannot be changed, written over or erased; most DVD-ROM discs are computer discs. A DVD-ROM is the same size as a CD-ROM but has more data capacity. It's like this a DVD-ROM is made of the same stuff as a CD-ROM, but it has more things. Have you ever wondered why your big TV has one cable but, your computer's got like 50? That's because computers have these little, tiny cables connecting to the monitor and stuff while, TVs have just one big one. Just like that DVDs are smaller than CDs so, they have fewer "cables" (or pits) on them than CDs do. So instead of having 100 cavities per millimeter of the disc surface, a DVD has only 30 or so and can hold much more information than CDs can!