Question: What is the purpose of gist and how is it different from regular code sharing/maintaining using GitHub?
GitHub is the entire site. Gists are a particular service offered on that site, namely code snippets akin to pastebin. However, everything is driven by git revision control, so gists also have complete revision histories.
Gist: Gist is a simple way to share code snippets and pastes with others. It is used when you need to share a sample piece of code or technique with your co-workers or friends.
GitHub GitHub, on the other hand, provides a platform to share an entire project as a repo among a team (private repo) or to the whole world (public repo).