I'm sure you have got a good idea about what, why, and when you can use branches when dealing with a Git repository. Let's fortify the understanding by creating a few use cases.
Suppose you are the training organizer in your organization and are responsible for conducting trainings as and when needed. You are preparing a list of people who you think might need business communication skills training based on their previous records.
As a first step, you need to send an e-mail to the nominations and check their availability on the specified date, and then get approval from their respective managers to allot the resource. Having experience in doing this, you are aware that the names picked by you from the records for training can have changes even at the last minute based on situations within the team. So you want to send out the initial list for each team and then proceed with your work while the list gets finalized.