what is rebase command in git code example

Example 1: git rebase

#The branches are like this
          A---B---C topic
         /
    D---E---F---G main
#git rebase <base> <target>
git rebase master topic
#<target> get moved forward on <base>
#NOTE: commits on <target> change their hash
                  A°--B°--C° topic
                 /
    D---E---F---G main

Example 2: what is git rebase

the rebase command integrates changes from one branch into
another. It is an alternative to the better known "merge" 
command. Most visibly, rebase differs from merge by rewriting
the commit history in order to produce a straight,
linear succession of commits.

Example 3: git rebase

$ git rebase --onto master server client