Prepositions of place describe the position of a person or thing in relation to another person or thing.
Look at this picture:
Now look at these example sentences:
There is a cup on the table.
The helicopter hovered above the house.
The police placed a sheet over the body.
He stood in front of the door and rang the bell.
Ram sat beside Tara.
A small stream runs below that bridge.
He put the key under the doormat.
He put his hands behind his back.