Try the new version with a few users
With a canary deployment, a small group of users gets the new version first. The team checks for errors and slowdowns before giving it to more people. If something goes wrong, fewer users are affected.
Prepare a replacement
With a blue-green deployment, the old version keeps running while the team prepares and tests the new one in a separate setup. When it is ready, the team directs users to the new setup.
They can work together
A team can try the new setup with a small group before switching everyone. Both approaches can make a deployment safer, but the team must watch for problems and have a recovery plan. Blue-green can cost more while both setups are running.