a point of convergence of light (or other radiation) or a point from which it diverges
the concentration of attention or energy on something maximum clarity or distinctness of an idea
- "the controversy brought clearly into focus an important difference of opinion"
- "the focus of activity shifted to molecular biology"
a central point or locus of bacterial growth in an organism
- "the focus of infection"
- smittpunkt [ medicin ]
a fixed reference point on the concave side of a conic section
(followed by on) to concentrate one's attention on something