Updating your Repositories

If you work on a feature for a long time you'll eventaully get behind upstream's master branch. To avoid conflicts later down the line you should pull the changes from master. To further help with avoiding conflicts you can rebase your repository. This essentially deletes all intermediate commits and combines them into one new commit.

$ git pull --rebase upstream master

This pulls the changes from upstream master into your local repository. Without the rebase option, if you have conflicts you will have to create intermediate commits called merge commits. This can make your project history messier and it's generally preferred that merge commits are avoided as much as possible.

Rebasing should never be done on the public repository as it deletes history but on your local repository it's acceptable if it helps keep the project history easier to read and maintain.

For more information on rebasing vs merging

https://www.atlassian.com/git/tutorials/merging-vs-rebasing