kb/oss
Open source licenses and contributing, explained simply: MIT, Apache, GPL, AGPL, and BSD. The role of CONTRIBUTING, CODE_OF_CONDUCT, and issue templates. Releases, tags, changelogs, DCO vs CLA. How to make your first contribution to someone else's project and how to accept the first PRs to your own.
A file in the repository root (or in `.github/`) that sets the rules for contributors: how to set up the environment, how to format commits, how to submit a PR. The clearer the CONTRIBUTING file, the fewer "how do I run this?" questions land in Issues.
Clone is a local copy of a repository. Fork is a copy **on the server** under your account. In open source you usually fork first (gaining write access to your copy), then clone the fork (to work locally), and open a PR from the fork back to the original.
The LICENSE file in the repository root defines the terms for using the code. Without a license, code is closed by default under copyright: you can view a public repository on GitHub (GitHub Terms of Service permit that), but you cannot copy, modify, or distribute it until the author explicitly grants permission. The most common licenses are MIT, Apache-2.0, and GPL.