A DVD player is an appliance that works under DVD-Audio and DVD-Video technical standards; two incompatible and different standards. In 1994, the very first DVD Player was invented.
Before invention of DVD players, there were VHS tapes that were used to play songs and videos. But now, because of DVD quality and portability, the VHS tapes are wiped out completely.
Types of DVD Players
DVD is coming out in all kinds of patterns. Here we are listing out several kinds of DVD players as well as recording devices, which are available for consumers.
• Universal DVD Player (DVD/SACD-Audio Compatible Player)
• Standard DVD Player (both changer and single tray)
• VHS VCR/DVD Player combination
• AV Receiver/ DVD player Combination
• VHS VCR/ DVD Recorder combination
• TIVO/ DVD Player combination
• Hard Drive/ DVD Recorder Combination
• TIVO/ DVD Recorder Combination
• Video Projector/ DVD Player Combination
• Video Game Console/ DVD Player Combination
• Portable DVD Player
• Home Theater-In-A-Box System along with built-in DVD Player
• DVD Player/TV or VCR/ DVD player/ TV Combination
• Standalone Video Editing System along With A Built-in DVD Burner
• DVD Camcorder
• HD-DVD Player (DVD and HD-DVD)
• DVD-Writer Drives DVD-ROM for Laptop and PCs
• Blu-ray Disc Player (DVD and Blu-ray Disc compatible)
How DVD Player Works
DVDs have same thickness and diameter as that of CDs, and they are developed by using some of the similar components and development techniques. Similar to a CD, the information on a DVD is written in the form of small bumps and pits on the disk.
A DVD comprises of different layers of 1.2 millimeters thick plastic. Every layer is developed by injection of molded polycarbonate plastic. This procedure creates a disc that has micro bumps organized as continuous, single and tremendously spiral form of data.
Every DVD has data; on a single layer-DVD, the tracks are always in the form of circles. Since, the DVD has data in circular tracks, to decode that data, the disc has to be inserted into player.
Once the DVD player is switched on, the disc starts rotating inside the player. An exclusive laser mechanism is used in the DVD player, and the laser keeps monitoring the rotating disc. With the help of optical energy, the data on the disc is encoded and comes out in the form of audio and video signals.
On the circular discs, the data is written in pits and once light falls on the pits, wherever it finds data, it decodes the same, and conversely doesn’t do anything with no data areas.
Storage Capacity of DVD
A DVD can store more data than CDs; it has multi-layer storage, less overhead, more area, and higher-density data storage.
You can find some more handy info on how DVD player works here:
http://electronics.howstuffworks.com/dvd.htm