What is the difference between DVD-ROM and DVD-R?

[hhamzeh]

Hi all,
Please correct me if I am wrong. The DVD movies that we buy or rent from stores are DVD-ROM and the blank DVDs that we use to back them up are DVD-R. So, does this mean that when we burn a DVD-R it becomes DVD-ROM? If this is correct, why all players are compatible with DVD-ROM but not all of them are compatible with DVD-R. Finally, If the DVD that we rent is totally something else, is there any burner that can burn that kind of DVDs. Thanks for your input.

[Cornucopia]

Physically,
They're different (ROM=Aluminum/Silvery Layer stamped/molded and sandwiched in plastic vs R=Laser activated Dye sandwiched between plastic vs RW=Laser actived Polymorphic Crystal sandwiched between plastic)

Optically,
R and RW are made to be close to IDENTICAL to ROM.

Structurally,
The main sections are identical, but the Pre-User data sections are different (ROM vs -R(Authoring) vs -R(General)/-RW vs +R/+RW vs RAM).

Logically (file-system and media layout),
They are IDENTICAL (Unless you're talking about DVD-VR recording, etc). All use Mode1 Data, ISO9660/microUDF bridge format, with VIDEO_TS folder with IFO/BUP and VOB files.

So, does this mean that when we burn a DVD-R it becomes DVD-ROM?

No.

If the DVD that we rent is totally something else, is there any burner that can burn that kind of DVDs.

No, they are pressed in a factory. Molded/stamped much like LP records or coins.

Scott