[FFmpeg-user] What is a "pad" in the context of an "input pad", an "output pad" and a "filter pad"

[Anatoly]

On Thu, 27 Oct 2022 15:57:59 -0400
Clay via ffmpeg-user <ffmpeg-user at ffmpeg.org> wrote:

> Dumb ffmpeg question alert:
> 
> What is a "pad" in the context of an "input pad", an "output pad" and
> a "filter pad"?
> 
> I understand the concept of padding a video with horizontal or
> vertical bars, padding audio with dead air or some other audio, but
> this is different.
> Is there a technical description of the actual term "pad" used to
> describe command line items in the ffmpeg execution string?
https://en.wikipedia.org/wiki/Contact_pad