"git add -A" is equivalent to "git add .; git add -u".

git init
echo Change me > change-me
echo Delete me > delete-me
git add change-me delete-me
git commit -m initial

echo OK >> change-me
rm delete-me
echo Add me > add-me

git status
# Changed but not updated:
#   modified:   change-me
#   deleted:    delete-me
# Untracked files:
#   add-me

git add .
git status

# Changes to be committed:
#   new file:   add-me
#   modified:   change-me
# Changed but not updated:
#   deleted:    delete-me

git reset

git add -u
git status

# Changes to be committed:
#   modified:   change-me
#   deleted:    delete-me
# Untracked files:
#   add-me

git reset

git add -A
git status

# Changes to be committed:
#   new file:   add-me
#   modified:   change-me