If you have for example a github directory in our home directory and want to update all the applications at the same time, instead of going in to every subdirectory and git pull from there. You can do every subdirectory at the same time

for i in */.git; do ( echo $i; cd $i/..; git pull; ); done
┌─[roger@parrot]─[~/github]
└──╼ $for i in */.git; do ( echo $i; cd $i/..; git pull; ); done