Codecs is a device that has both coder and decoder. A video codecs is a device specifically designed for video applications such as video conferencing and video editing. It converts analog video signals or data into a digital format, 1 and 0 so that it can be transmitted on a digital channel. On the transmitter side, the coder is doing its job by converting the analog video signal to digital data. On the receiver side, the digital formatted video signal is extracted and reprocessed by the decoder to get the original analog video signal. A decent video codecs must have a high-quality sample rate. It should have high dynamic range and excellent signal to noise ratio.

There are two classifications of video codecs: the lossy and lossless video codecs. A lossy video codecs uses lossy compression technologies. A lossy video codecs cannot reprocess the original video quality; instead it gives a facsimile of the original file. On the other hand, lossless video codecs reproduces the exact file as the original during decompression.

One of the most popular video codecs compression/decompression techniques is the Motion Picture Expert Group (MPEG). The MPG, M15, MP2, M1V are all derived from this family. Another popular video codecs compression and decompression techniques are DivX and XviD. DivX is commonly used in DVD while XviD is an open source version of DivX.