A recordable DVD-R is an optical disc that can be used to permanently store files, music or movies by transferring them from a computer and burning them to disk. A recordable DVD-R looks like a compact disk (CD) but can hold more data and is just one of several types of DVDs, or Digital Versatile Disks, formerly Digital Virtual Disks. The term "recordable DVD-R" is redundant since the "R" stands for recordable, but the term is often used and so will be used here for the reader's convenience, though the correct usage is simply DVD-R.
The dash in "-R" indicates that the disk is formatted according to the "minus" or "dash" standard. Pioneer created this standard in 1997, while a competing recordable format is the DVD+R ("plus") format, available since 2002, created by the DVD+RW Alliance. The plus standard incorporated many improvements over the minus standard that resulted in more reliable recordings. A DVD formatted to the plus standard is less likely to give errors when recording, when playing back at high speeds, or when using multi-session recording.
A recordable DVD-R has a capacity of 4.71 Gigabytes (GB), allowing it to store about six times more data than a CD with a 700 Megabyte (MB) capacity. The DVD can hold more data because the pits and lands on the writeable surface that act as digital ones and zeros are smaller on a DVD, allowing more information to be packed in tighter. The smaller pits and lands also required a finer laser beam, which is why CD players could not play DVDs and had to be manufactured specifically to support both types of disks.
Virtually all DVD players are compatible with the recordable DVD-R format, but vintage players will not be able to play a DVD+R disk. Even following 2002 some players were only manufactured to support the original standard. Today most players support both standards, indicated by the presence of both a plus and minus within the specifications of the product. Most manuals do recommend specific brands of recordable DVD-R or DVD+R disks, and following these recommendations can result in fewer errors.
A recordable DVD-R disk cannot be erased. If the amount of data burned to disk does not exhaust the disk’s capacity, further recording can be done using multi-sessions until the disk becomes full. However, data already present cannot be changed or overwritten. To do this a DVD-RW or DVD+RW is required. The “RW” stands for “rewriteable” and these disks are commonly more expensive than record-only disks.
Another type of recordable DVD-R is the dual layer (DL) disk. A dual layer DVD utilizes two writing surfaces, doubling capacity. Not all DVD burners support DL technology, so before buying recordable DVD-R DL disks, check the manual. A further consideration is whether you will need the disk to play in other DVD units, including the home entertainment center or a friend’s player. Dual layer disks also cost more than standard DVD-Rs.