>>73874556To keep it simple, think of it like a lockbox full of jewels, the codec is the jewels, and the lockbox is the format you recognize as webm, mp4, mkv, etc. Most commonly used lockboxes are custom-fit for their jewels (h264/mp4 and vpx/webm) so that's generally why most people don't know the distinction. You'll notice most anime is shared as MKV, because it's basically a cardboard box where you can put anything in it.
