Github is a git platform, the largest one, in fact. Anyone can make a github account and create git repositories where they upload their code, you need a paid account to make private repositories. What are you looking for? How do use software you find there or how to make software and upload it? More on reddit.com

I work on multiple devices in multiple locations, when I‘m done, I push to github, switch the device and pull. I have my code everywhere. And in terms of webdev everytime I push something to the master branch my site gets built and deployed automatically. This is what I use github for More on reddit.com

Git is a "version control system." It lets you keep track of everychange you've made to your codebase, and assists with keeping multiple developers' versions of the same codebase in sync and up-to-date. Accidentally make a change that breaks production? You can revert it with Git. You and your coworker both make a modification to the same file? Git can usually merge them automatically for you, or at the very least give you a good breakdown of where your changes conflict. GitHub is a Git server. It's a remote location where you can host code that is stored in Git. It also provides issue tracking, and a nice frontend for managing incoming changes to your repository in the form of pull requests. But GitHub is not the only Git server; there's also GitLab, Gitea, BitBucket, Gogs... all of which have their own advantages and disadvantages. GitHub is by far the most common for everyday use, but it definitely isn't the only one, and you shouldn't base your learning of Git around any one Git server. late edit: If you're looking for a good simple crash course in Git, MIT has you covered as part of their free "Missing Semester of your CS Education" course. Definitely worth a look (although it's by no means a definitive guide to all things Git). More on reddit.com

Stacked pull requests break large changes into small, reviewable pull requests. I still don't really understand this. I ask this genuinely wanting to know what I'm missing: isn't that what commits are for? If people aren't using the commits in a pull request like this, what are they using them for? I thought git was pretty much designed around rewriting history, so that the final commits represent semantically-meaningful changes to the codebase, rather than a step-by-step log of how the developer wrote those changes. Are people sending PRs that simply contain all of their local "whoops, typo" commits? Are they just squashing the whole PR in to one big commit? More on reddit.com