An AVC can mean different things depending on context, but the two most common everyday uses are:

  • Technology / video : AVC stands for Advanced Video Coding , also known as H.264 or MPEG‑4 Part 10. It is a widely used video compression standard that shrinks video file sizes while maintaining high visual quality, and is used for recording, streaming, and distributing video up to 8K resolution.
  • Pensions / finance (UK & Ireland especially): AVC stands for Additional Voluntary Contribution. It is an extra, optional payment you make into your pension on top of your normal contributions, usually via your employer’s scheme, to build up a larger retirement pot in a tax‑efficient way.

Because your title is “what is an avc” with no extra context, most people online are either asking about the video format (when dealing with files, streaming, cameras, editing, YouTube, etc.) or the pension top‑up (when talking about salary, retirement, or workplace schemes).

If you tell me the context (video file on your device vs. workplace pension paperwork vs. medical/health), I can narrow it to the exact meaning that applies to you.