He was standing behind me.
There is a small garden at the back of the house.
There's a car behind the house.
He turned around and laughed.
Please step back one step.
I was called out to from behind.
I stood behind the teacher.
後ろ is the everyday, casual word for 'behind', while 後方 is more formal and typically used in written, military, or technical contexts.
後ろ is the general everyday word for 'back' or 'behind', while 後部 is a more formal term specifically for the rear section of a vehicle, vessel, or object.
right behind; directly behind
hind leg; hind foot
hair on the back of one's head
with hands behind one's back · behind; rear; back
backbiting; criticizing behind one's back
front and back; before and after
rear right; back right; right and behind
rear left; back left; left and behind
back side; rear; back end
backwards; back to front; inside out
retreating figure; back of a person walking away
backing; support; patron · shield that protects one's back
back of a collar · grabbing the back of the opponent's collar (in judo)
crying over spilt milk; complaining about the past · backbiting; malicious gossip
rear basket (e.g. on a bicycle)
postponement; moving back (a schedule)