Encoder (video) - An encoder is a program and/or device used to change a signal, or stream of data, into a code that a compatible computerized device at the receiving end can work with. Often this includes "compressing" a certain amount of the content.

The code the encoder produces may be further manipulated in the network for optimal results. This encoded data typically needs a "decoder" at the receiving end to change it into a signal or data stream that a TV or other applicable device can understand. (Analog TVs don't understand digital signals unless the signal is "decoded" by a computerized device for them.)

TV providers encode their TV signal as part of the process of sending it to their subscribers.

Multiplexing technologies are often used in the TV provider’s encoding process. Multiplexing is a general term for combining types of data and/or signals and sending it to a receiver(s).

Computerized encoding for transmission might be known as a "multiplexing." http://en.wikipedia.org/wiki/Encoder


Codec

Decoder

Lossy Compression

Lossless Compression (Nonlossy Compression)

Multiplex