In mathematics, a "classification" means making a list of all possible objects of a given type.
Classification results are some of Ciro Santilli's favorite: Section "The beauty of mathematics".
Examples:
- classification of finite simple groups
 - classification of regular polytopes
 - classification of closed surfaces, and more generalized generalized Poincaré conjectures
 - classification of associative real division algebras
 - classification of finite fields
 - classification of simple Lie groups
 - classification of the wallpaper groups and the space groups
 
 Tagged
- Classification of closed surfaces
 - Classification of finite fields
 - Classification of finite rings
 - Classification of finite simple groups
 - Classification of Pythagorean triples
 - Classification of regular polytopes
 - Classification of simple Lie groups
 - Frobenius theorem (real division algebras)
 - Generalized Poincaré conjecture
 
Ciro Santilli