Physically similar to an oversized CD, virtually every LaserDisc player manufacturered since 1986 will also play conventional CDs. Because of these playback limitations, movies over two hours in length are usually recorded on two or more discs. Both Dolby Digital and DTS were first used on LaserDisc.
Many discs also contain extra features such as production material and director's commentary.
DVD is capable of approximately 500 lines of horizontal resolution, compared to VHS's 240, Super VHS's 400 and LaserDisc's 425. For more be sure to read Jim Taylor's excellent DVD FAQ Page . Dolby Pro Logic Developed in the mid-1980s by Dolby Laboratories, Dolby Pro Logic is essentially the domestic version of Dolby's theatrical 'Dolby Stereo' system. Not all channels can contain all frequencies at the same time, and channels must interact with one another to varying degrees. To overcome these limitations, fully discrete systems such as Dolby Digital and DTS Digital Surround were developed.