MPEG-4 AVC - (a.k.a. MPEG-4 Part 10, H.264) - (May be known as Low bit-rate Streaming Protocol) - AVC stands for Advanced Video Coding and is a digital video codec standard known for achieving a high level of data compression. The high H.264 coding efficiency enables video to be compressed to such low bit rates that the compressed video can be transferred through networks using a smaller amount of bandwidth.
H.264 provides high-quality video across the bandwidth spectrum. H.264 can be used by a number of different devices including narrowband (which is the opposite transmission speed of broadband) cell phones and broadband set-top boxes. It can also be used to broadcast HDTV.
AVC is the latest version of MPEG-4 (as of March, 2006) and contains new features that compress video much more effectively than older standards, (without compromising image quality.) AVC can offer an increased number of HD channels and it's development coincides with today's increased HDTV distribution. (Do note that MPEG-2 can also be used for HD transmission.)
At the time of this writing, H.264 compression technology could utilize up to 40 percent less network bandwidth than MPEG-2 compression. (Reference)