Digital video is being adopted in an increasing range of applications including video telephony, security/surveillance, DVD, digital television, Internet video streaming, digital video camcorders, cellular media, and personal video recorders. Video compression is an essential enabler for these applications and an increasing number of video codec (compression/decompression) industry standards and proprietary algorithms are available to make it practical to store and transmit video in digital form. Compression standards are evolving to make use of advances in algorithms and take advantage of continued increases in available processing horsepower in low-cost integrated circuits such as digital media processors. Differences exist in the compression standards and within implementation of standards based on optimizations for the primary requirements of the target application. This paper provides an overview of the different compression standards and highlights where they are best suited. It also provides an overview of compression rules of thumb for different standards and the corresponding performance requirements for real-time implementations.