Codec stands for compressor/decompressor. Compressor refers to encoding a file and is synonymous with capture and rendering. Decompressor refers to decoding a file and is associated with playback. Codec denotes a particular compression scheme—a method of compressing and decompressing a file.
In general, you have a choice of software and hardware codecs. QuickTime and Video for Windows include several software-based codecs; others are available as software plug-ins (Figure 18.23).