focal point focal point /ˈfoʊkəl pɔɪnt/

noun

1. () A point of convergence of light (or other radiation) or a point from which it diverges  ( focus , focal point )
   a point of convergence of light (or other radiation) or a point from which it diverges
   
2. The concentration of attention or energy on something  ( direction , focal point , focussing , centering [American] , focus , focusing , centring [Canadian, British] )
   the concentration of attention or energy on something
    The focus of activity shifted to molecular biology
   the focus of activity shifted to molecular biology
    He had no direction in his life
   he had no direction in his life
   
3. A central point or locus of an infection in an organism  ( focal point , nidus , focus )
   a central point or locus of an infection in an organism
    The focus of infection
   the focus of infection