What does 'git checkout -b branch-name v1.0' do?

The command git checkout -b branch-name v1.0 performs the following actions in Git:

1. Create a New Branch: The -b option indicates that you want to create a new branch. In this case, the new branch will be named branch-name.

2. Base the New Branch on a Specific Commit: The v1.0 part specifies that the new branch should be created based on the commit that the tag v1.0 points to. This means that the new branch will start from the state of the repository at the time of the v1.0 tag.

3. Switch to the New Branch: After creating the new branch, Git will automatically switch your working directory to this new branch, allowing you to start making changes based on the state of the repository at the v1.0 tag.

In summary, this command creates a new branch called branch-name from the commit associated with the v1.0 tag and checks out that new branch for you to work on.