Let me try to explain in as simple a way as possible.
When CD and DVD players became part of computers, we realised you could play Music as well a Video on the computer also. With something like the iPod, you could actually carry your music with you.
Music that originally comes in CD and movies that come in DVDs have a particular storage format. For various reasons including transportability, these are converted into computer file formats such as MP3, AVI etc. These are called codecs or containers, though both are not the same. These are also loosely called media.
Essentially you need a computer or a specialised processor to play these file formats. At home, though you can use a computer, the overheads (of a computer) used just to play some audio and video files is too expensive. Some companies such as Sigma Design, Realtek and other designed and made what are called System-On-Chip or SOCs. Essentially these are special processors that have a small OS, application software, and most important, the capability to understand, decode, and play audio and video media.
These chips are taken by some 110 odd companies around the world who design and manufacture a player. These player usually are small in size, have a chip from one of these companies, can read media files, and play them on your TV, amplifier etc. Some of the players also come with a DVD or a Blu-Ray drive that allows you to play the optical media also.
Media files can be made by you yourself through a process called ripping using a computer. You insert a CD or DVD, and an application will extract the AV information and write it on your HD in the format of your choice. One of the advantages of creating such a file is that you can use it as many times as you like without any degradation is sound or video quality.
For a detailed list of all media players visit
iboum.com : Future Entertainment Technology : Home.
Cheers