DVD stands for Digital Versatile/Video Disc, DVDR stands for DVD Recordable and DVDRW for DVD eWriteable. If you're familiar with regular audio/music CDs or regular DVD-Video discs, then you will know what a recordable DVDR/W looks like. A recordable DVDR/W stores up to 2 hours of very good quality DVD-Video, including several audio tracks in formats like stereo, Dolby Digital or DTS and also advanced menu systems, subtitles and still pictures that can be played by many standalone DVD Players and most computer DVD-ROMs. If you choose to lower the video quality it is possible to store several hours video on a recordable DVDR/W using low bitrates and low resolution with video quality more like VHS, SVHS, SVCD, CVD or VCD. It is also possible to have up to 4.37* GB ordinary data or mix DVD-Video and data on a recordable DVD that can be played by most computer DVD-ROMs.
There are three competing DVD Recording standards, DVD-R/W and DVD+R/W have pretty similiar features and are compatible with many standalone DVD Players and most DVD-ROMs while DVD-RAM has less DVD Player and DVD-ROM compatibility but better recording features.
DVD-R and DVD-RW
DVD-R/W was the first DVD recording format released that was compatible with standalone DVD Players.
DVD-R is a non-rewriteable format and it is compatible with about 93% of all DVD Players and most DVD-ROMs.
DVD-RW is a rewriteable format and it is compatible with about 80% of all DVD Players and most DVD-ROMs.
DVD-R/W supports single side 4.37 computer GB* DVDs(called DVD-5) and double sided 8.75 computer
GB* DVDs(called DVD-10).
These formats are supported by DVDForum.
DVD+R and DVD+RW
DVD+R/W has some "better" features than DVD-R/W such as lossless linking and both CAV and CLV writing.
DVD+R is a non-rewritable format and it is compatible with about 89% of all DVD Players and most DVD-ROMs.
DVD+RW is a rewritable format and is compatible with about 79% of all DVD Players and most DVD-ROMs.
DVD+R/W supports single side 4.37 computer GB* DVDs(called DVD-5) and double side 8.75 computer
GB* DVDs(called DVD-10).
These formats are supported by the DVD+RW Alliance.
DVD+R DL or called DVD+R9 is a Dual Layer writeable DVD+R. The dual layered discs can hold 7.95
computer GB* (called DVD-9) and dual layered double sides 15.9* computer GB (called dvd-18).
DVD-RAM has the best recording features but it is not compatible with most DVD-ROM drives and DVD-Video players. Think more of it as a removable hard disk. DVD-RAM is usually used in some DVD Recorders.
This format is supported by DVDForum