flutter channel shows
stable
Channel for stable builds. It’s the recommended channel for product development.

beta
Channel for best build of the previous month.

dev
Channel for latest fully tested build. More tests are run in this channel than master.

master
Channel for active development with latest changes. If you want to try the latest features,
this is the channel to track. Code in this channel usually works, but sometimes it may break
accidentally. Use this channel at your own risk.
flutter channel master

flutter upgrade