Switch over to the branch "issue1" when you want to add new commits to it.
Use the checkout command to switch branch.
$ git checkout
Switch to the branch "issue1" by doing the following.
$ git checkout issue1
Switched to branch 'issue1'
This history tree should look like this at the moment.

By passing in the -b option when executing the checkout command, a new
branch will be created and you will be switched over thereafter.
$ git checkout -b
Once you are on the "issue1" branch, you can start adding commits to it. Let's add the bold text below to myfile.txt and commit the change.
Git commands even a monkey can understand
add: Register a change in an index
$ git add myfile.txt
$ git commit -m "append description of the add command"
[issue1 b2b23c4] append description of the add command
1 files changed, 1 insertions(+), 0 deletions(-)
Our history tree will now look like this.
