Updated April 10, 2017. In grammar, a demonstrative is a determiner or a pronoun that points to a particular noun or to the noun it replaces. There are four demonstratives in English: the near demonstratives this and these, and the far demonstratives that and those. This and that are singular; these and those are plural.
In the context of video compression, codec is a concatenation of encoder and decoderâa device that only compresses is typically called an encoder, and one that only decompresses is a decoder. The compressed data format usually conforms to a standard video compression specification.
2) The term codec is also an acronym that stands for  co mpression/ dec ompression.. A codec is an algorithm, or specialized computer program, that reduces the number of bytes consumed by large files and programs.In order to minimize the amount of storage space required for a complicated file, such as a video, compression is used. Compression works by eliminating redundancies in data.) In communications engineering, the term codec is used in reference to integrated circuits, or chip s that perform data conversion.