DVDs are formatted for use on two conflicting regional television systems: 525/60 (NTSC) or 625/50 (PAL/SECAM). NTSC is the TV format used in Canada, Japan, Mexico, Philippines, Taiwan, United States, and other countries. PAL is the TV format used in most of Europe, most of Africa, China, India, Australia, New Zealand, Israel, North Korea, and other countries. Some DVD players only play NTSC or PAL discs, while others can play both standards.

In general, it is easier for consumers in PAL countries to view NTSC DVDs than vice versa. Almost all DVD players sold in PAL countries play both kinds of discs, and most modern PAL TVs can handle the converted signal. However, most NTSC players can't play PAL discs, and most NTSC TVs don't work with PAL video. Those in NTSC countries, such as in North America, generally require both a multi-standard player and television to view PAL discs, or a converter box. There are also differences in pixel aspect ratio (720x480 vs. 720x576), display frame rate (29.97 vs. 25), and surround audio options (Dolby Digital vs. MPEG audio). Again, NTSC discs (with Dolby Digital audio) play on over 95% of DVD systems worldwide, while PAL discs play on very few players outside of PAL countries.

Most DVD PC software and hardware can play both NTSC and PAL video and both audio standards.

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