Keep your fork in sync. with original master :
# Now, you are in your local cloned copy of original GitHub repo:
git checkout master
You wish to update master to be in sync with original GitHub repo.
# First, add github location as "remote" (1) - here *upstream* is the name provided by us:
git remote add upstream https://github.com/original-repo-from-where-you-cloned.git
# fetch all branches - see we are using name provided above :) (2)
git fetch upstream
# apply all changes from original github location to your branch and then play your changes on top (3)
git rebase upstream/master
Now your fork is in sync with original repo :)
(1) git-remote add
Adds a remote named <name> for the repository at <url>. The command git fetch <name> can then be used to create and update remote-tracking branches <name>/<branch>.
(2) git-fetch - Download objects and refs from another repository
(3) git-rebase - Reapply commits on top of another base tip