Optical disc technology has moved on a long way from the original CD parameters laid down in the late 1970s. Advances in laser design and optics, together with the experience gained in disc manufacture, allow a smaller and more compressed pit pattern on a tighter track pitch.

Like CDs, DVDs can be 120 or 80 mm in diameter. They can be single or double sided, and each side may carry either one or two layers of data. In the basic single-layer, single-sided format, the 120 mm disc has a capacity of 4.7 Gigabytes, compared to the 680 Megabytes of the equivalent Compact Disc. This represents a gain factor of 7.3. The capacity of the 8 cm disc increases by the same factor (1.46 GB as against 200 MB). By defining both dual recording layers on a single-sided disc, and single or dual layers on a double sided version, the DVD specification allows for a potential capacity of almost 20 Gigabytes (17.8 GB).

The bit size and track pitch for DVD, thanks to advances in laser, lens replication technology, have been reduced to less than half those at for CD. At the same time, encoding efficiency, thanks to a new sector format, error correction code, and channel modulation scheme, is up by a factor of 1.5. The size of the disc's program area is also slightly larger. The rest of the gain in data capacity was reached by significantly reducing the manufacturing tolerances for the discs, and also for the drives. Years of experience of CD manufacture, in which Philips is unequalled, put these well within reach. The acual data on a disc is organised in the highly-efficient UDF-Bridge file format, specially designed for DVD, which also allows compatibility with existing CD-ROMs, Recordables and ReWriteables, and future DVD Recordables and ReWriteables. The video data itself is in the high-compression MPEG2 format, which ensures that full-length movies at high picture quality can be recorded on a single disc. It is accompanied by MPEG2 Compatible Multichannel Audio, which can handle the digital 5.1 multichannel audio systems already installed in some Home Theatres, as well as the 7.1 systems present at the moment only in leading movie houses, or by Dolby AC-3 digital 5.1 multichannel sound.

To make sure of accurate readout of the far finer pit pattern, DVD discs need high rigidity. This is achieved by bonding two 0.6 mm substrates back-to-back to make a standard 1.2 mm thick disc. Already well known from LaserDisc - another Philips development - this technique gives the DVD the necessary robustness against changes in temperature and humidity.