Here are some Git terminologies we should be familiar with: 

• Ref: The name that begins with refs that point to an object.
• Repository: A database that contains all of a project's information, files, metadata, and history. It contains a collection of ref for all the collections of objects.
• Branch: An active line of development. The most recent commit is the tip or the HEAD of that branch. A repository can have multiple branches, but your working tree or working directory can only be associated with one branch. This is sometimes referred to as the current or checked out branch.
• Checkout: The action of updating all or part of the working tree to a particular point.
• Commit: A point in time in Git history, or it can mean to store a new snapshot into the repository.
• Merge: The action to bring the content of another branch into the current branch. For example, I am merging the development branch with the master branch.
• Fetch: The action of getting the content from a remote repository.
• Pull: Fetching and merging a repository.
• Tag: A mark in a point in time in a repository that is significant. In Chapter 7, The Python Automation Framework – Ansible Basics, we saw the tag used to specify the release points, v2.5.0a1.

This is not a complete list; please refer to the Git glossary, https://git-scm.com/docs/gitglossary, for more terms and their definitions.