In order to know the meaning of the term decoder it is necessary, first, to discover its etymological origin. In this case, we can establish that it comes from the word “decode”, that it derives from Latin and that it is the result of the sum of three clearly differentiated parts:
-The prefix “de-”, which comes to indicate “from top to bottom”.
-The noun "codex", which can be translated as "register" or "code".
-The verb "facere", which is synonymous with "doing".

The concept of decoder , which can also be mentioned as decoder , Alludes to what decodes (or decode). He verb decode, meanwhile, refers to the reverse application of the rules of a code to a message that is encoded in order to achieve its original form.
The notion is usually linked to a device that allows decoding. A decoder, in this sense, is a circuit which accepts coded inputs and activates the corresponding outputs according to the code in question.
When we talk about decoders we can establish that, at present, there are three important types of satellite decoders such as: ITPV decoders, 4K decoders and DTT decoders.
Take the case of a decoder that receives a binary coded digital input . This device can activate different outputs, according to the code That was applied to the entrance. A 3-bit code, to name a case, has 3 entries and 8 possible combinations. Each combination activates only one output: the decoder accepts an input with a certain code in binary and then activates the corresponding output.
It is easy to understand how a decoder works if we think about the devices used in the televisions . These decoders receive an encoded signal that is broadcast by fiber optic or satellite. Bliss signal it cannot be seen on any television: a decoder capable of decoding the code is needed to make it visible. In this way, when the decode receives the signal (input), it decodes it and makes it visible (output) on the television to which it is connected.
It is common for some TV signals to be transmitted encoded so that only those can be viewed people that have a decoder and pay the fertilizer correspondent.
When buying a satellite decoder, it is necessary to take into account a series of requirements such as the brand that guarantees that, the type of decoder that is, that is compatible with new technologies, that has at least one USB type input and that it has a price that is consistent with the money that can be spent and that is consistent with market prices.
In the same way, we must pay attention to what are the functions performed by the mentioned device, such as recording or programming a program, and the accessories with which it is presented.
Playback quality, image display options, whether or not it presents remote control and even the type of connection it offers are also aspects to take into account.