A codec is a device or program that compresses or decompresses a digital data stream. Codecs are used in a wide variety of applications, including audio and video compression, data storage, and network transmission. Codecs work by breaking down a data stream into smaller pieces and then applying a compression algorithm to each piece. The compressed pieces are then stored or transmitted, and the decompression algorithm is used to reconstruct the original data stream when it is needed.
Codecs are essential for making digital data manageable. Without codecs, it would be impossible to store or transmit large amounts of data, such as high-quality audio and video. Codecs also play a vital role in network transmission, as they can reduce the amount of bandwidth required to transmit a given amount of data.