Enumerative geometry

In mathematics, enumerative geometry is the branch of algebraic geometry concerned with counting numbers of solutions to geometric questions, mainly by means of intersection theory.

Quotes

 * Enumerative geometry is an old subject that has been revisited extensively over the past 150 years. Enumerative geometry was an active field in the 19th century. … Unfortunately, many fundamental enumerative problems eluded the best mathematicians for most of the 20th century. Progress came from a seemingly unlikely source: string theory in physics.