This is the 4468th most frequent Turkish word.
arkasına
"Arkasına" means "to its/his/her back" or "behind it/him/her."
Here 'arkasına' means 'to the back of,' indicating a location behind an object.
Kedi sandalyenin arkasına saklandı.
The cat hid behind the chair.
In this sentence, 'arkasına' indicates the position 'to behind' or 'to the back of' the door.
Kapının arkasına bir not bırakmış.
He left a note behind the door.
Here 'arkasına' conveys the position 'to behind' someone, signifying being positioned at the back in the spatial context.