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.