Stable is the production-ready release updated every six weeks, Beta is the pre-release candidate for testing, and Nightly is the daily build containing experimental features. Use Stable for production code to ensure compatibility, Beta to test upcoming changes, and Nightly only if you need unstable features behind feature flags. You can switch between these channels using rustup with the following command:
rustup default stable
To install a specific channel, replace stable with beta or nightly in the command above.