A profile is a limited, specific implementation of a standard. Standards often permit a wide array of possible implementations; profiles implement a specific configuration of values selected from the range of values provided by the standard.

For example: MPEG-4 is an international audio-video encoding standard (ISO/IEC CD 14496); MPEG-4 Part 2 deals specifically with encoding video. MPEG-4 Part 2 standards specify that media should be encoded between 64 and 8000 kilobits of visual data per second (kbit/s), a range of data rates that accommodates anything from the audio stream of a digital telephone to the video stream of a DVD video (at 40,000 kbit/s, Blu-Ray video is well beyond the scope of MPEG-4 Part 2 and instead conforms to Part 10 of the MPEG-4 standard).

To simplify things, the MPEG-4 Part 2 standard lists several specific implementations, or profiles, of the MPEG-4 Part 2 standard, each of which specifies a maximum bitrate (in concert with other variables, such as frame rate, that are not included here):

• Simple Profile: 64-384 kbit/s, maximum
  • Level 0: 64 kbit/s, maximum
  • Level 0b: 128 kbit/s, maximum
  • Level 1: 64 kbit/s, maximum
  • Level 2: 128 kbit/s, maximum
  • Level 3: 384 kbit/s, maximum
• Advanced Simple Profile: 128-8000 kbit/s, maximum
  • Level 0: 128 kbit/s, maximum
  • Level 1: 128 kbit/s, maximum
  • Level 2: 384 kbit/s, maximum
  • Level 3: 768 kbit/s, maximum
  • Level 3b: 1500 kbit/s, maximum
  • Level 4: 3000 kbit/s, maximum
  • Level 5: 8000 kbit/s, maximum

So, digital video encoded at 1200 kbit/s would conform to Level 3b of the Advanced Simple Profile of the MPEG-4 Part 2 standard.