[Git] About Rebase

git pull --rebase

This command will get rebase the remote branch with the local branch.

Before

        D --- E  local branch
       /
A --- B --- C  origin branch

After

              D --- E  local branch
             /
A --- B --- C  origin branch

git rebase --onto master server client

This will "Check out the client branch, figure out the patches from the common ancestor of the client and server branches, and then replay them onto master." (From here). That is to say:

The parts H, I, J will be picked up and add to the master branch.
Why pick up the H, I, J? Because the client and server have the same ancestor D, "from the common ancestor" that is to say from D.

Before

A --- B --- C  master 
       \
        D --- E --- F  server
         \
          H --- I --- J  client

After

              H --- I --- J  client
             /
A --- B --- C   master 
       \
        D --- E --- F  server