git-7_merge remote change

$git fetch        #get remote repo change,local branch head will not change
$git fetch –a     #get all HEAD/Tag/Branch change from remote repo
$git merge remotes/origin/build_llv #merge remote change to local
$git pull         # this command = git fetch+git merge
$git pull –rebase #merge remote modification, recommended. 
$git rebase -i  #rebase with interaction, you can squash the commits

Note: git pull will add another new commit to denote that the merge happened.