Uses of the preposition ~below~

1. If sth is below sth else, it is in a lower position.  
           

    In an adjunct or after 'be': It lay a mile below the surface of the Pacific  
    Ocean......Below us on our left there was a big river.....a bruise just below the elbow. 

   After a noun: .....when man first came to live in caves below cliffs

   Also used as an adverb: Then heard it hit the surface of the water far below

2. If sth is below a rate,amount or level it is less than that rate amount or level

     In an adjunct or after a link verb: Few experts expect their share to dip below 

     20 percent....You cannot go below absolute zero........He, for a man, seemed just below 

     average height

     Also used as an adverb: Keep the room temperature 68 or below

3. If someone is below you in an organization or system of assessment. they are

     lower in rank 

     In an adjunct or after 'be' :  I believe he is a genius, somewhere above Eliot but   
     below  Shakespeare