In a common sense codecs are certain devices or even computer specifically designed program created for procersses od encoding/decoding of data, digital packets, signals or streams. Codecs are the programs (should not be confused with format) designed to read, write, or re-write files or digital standards. Codecs encodes a data packages or signals for emitting, transmission and storage; codes decodes it for mounting them in reciprocals sequence in order to ensure a playback or for process of editing. Codecs are usual applications within videoconferencing, video streaminin and/or video editing. So, for instance, video camera’s ADC (Analogue-to-Digital Converter) transforms associated analog signals into digital ones, which are then transmitted through a specific device named video compressor for further digital transmission or storage. A receiving appliance then gets the signal via video decompressor, then a DAC (Digital-to-Analogue Converter) for display. The definitions codecs in this case is being used as a generic labeling for a video conferencing unit.

Historically (in 50ies) Codecs meant hardware designed for coding of signal into so called PCM (Pulse Code Modulation) and decoding it back. However, currently, word codecs means the software with organic and integrated compander functionalities. A modem is a unity of modulator/demodulator functionalities and converted digital data from PCs to analog ones for phone line transmission. On the arrival end the analog was transformed back to digital. Codecs do just the opposite, converting analog signal (for instance audio or speech)to digital one and then computer digital sound back to audio). Audio codecs makes analog audio signals to appear as digital ones for transmission or storage. A video codecs make the same procedures for video signals. Some codecs are labeled to be as ‘’Lossy codecs’’: meaning that they decrease quality significantly in order to reach some level of signal compression. Normally, this Codecs type is indistinguishable from the uncompressed sounds or files, depending on the particular codecs and their configurations. Smaller data package makes easier the operational procedures of codecs without discrepancies. Lower data transmiiting rates also improve operational performance of codecs when the data is processed. Another kind of codecs is being named a ”Lossless codecs”: normally used for archiving data in a compressed packages while retaining all of the original information present. When retaining the original quality of the data stream is more important than eliminating larger data sizes, lossless codecs should be selected for use. This is vital when data is to undergo editing or further types of additional processing, where repeated application of encoding and decoding on lossy codecs will decrease the quality of the resulting data up to identifiable level.

Using more than one codecs or encoding algorithms successively can also dilute quality a lot. The dropping operational cost of storage capacity and network bandwidth has a trends to reduce the demand for lossy codecs for media. Media Codecs are often created to stress up on the certain aspects of the media. For instance, a digital video (using a DV codecs) of a sports event has to encode factual motion with a good quality but not necessarily exact colors, while a video of an art museum needs to demonstrate perfectly encoding color and surface texture. Audio codecs for mobile phones have to have very low level of latency when processing the source encoding and further playback; however audio codecs for sound recording can utilize high-latency codecs algorithms to get higher fidelity at a lesser bit-rate.