Here's an easy way to see how this works. Run this script:

echo dollar-star: for i in $; do echo $i; done echo dollar-at: for i in $@; do echo $i; done echo quoted-dollar-star: for i in "$"; do echo $i; done echo quoted-dollar-at: for i in "$@"; do echo $i; done

./x.sh a "b c" d dollar-star: a b c d dollar-at: a b c d quoted-dollar-star: a b c d quoted-dollar-at: a b c d