For a detailed explanation of this process view this document. In short, the algorithm removes the data pertaining to sounds that a human ear cannot detect. The manner in which MD's are loaded into a player.
Some variations do exist.
Panasonic also has a slight varation of the clamshell design, where a small latch is added to keep the player closed in moving environments. The ESP memory is also resistant to vibration itself, thus making it capable of providing a continous stream of digital audio data. When a player is turned off, the current location on the disc is stored in the player's memory. When the play button is pressed at a later time, the player will automatically resume where it last left off, given that the same CD or MD is in the player.