Learn how to integrate changes from one branch into another.
Once you have completed your work on a feature or bug-fix branch, you'll want to integrate those changes back into your main codebase (e.g., the `main` branch). The `git merge` command is used to combine the history of two or more branches into a single branch. The typical workflow is to first switch to the branch you want to merge *into* (the receiving branch), and then run the `git merge <source-branch-name>` command. For example, to merge the `dev-feature` branch into `main`, you would first `git checkout main` and then `git merge dev-feature`. Git will look at the commits on both branches and attempt to combine them. If the changes on the two branches are on different lines of code or in different files, Git will often be able to merge them automatically, creating a new 'merge commit' to tie the histories together. This process allows for a safe and controlled way to integrate new code into your project.