In a nutshell, Pandoc is an open-source document converter, converting between different document formats such as markdown, pdf, html, docx, and ePub.
Hence the name: "Pan" (all / everything) "doc" (documents)
It's a potentially useful workflow tool. For example, converting markdown notes into publishable web pages or PDFs.
Simple introductory [YouTube video: Pandoc Crash Course](https://www.youtube.com/watch?v=bHMIL822NVs)
Example of using Pandoc in the shell to convert html to markdown:
```zsh
# -f "from", -t "to", -o "output"
pandoc my-doc.html -f html -t markdown -o my-doc.md
```