Several typologies of negative ions are presented paradigmatically for simple atomic and molecular systems. Basic principles of negative ion stabilities are discussed for three-particle Coulomb systems and the issues of electron correlation and relativistic effects are addressed for atoms. Weakly bound and Feshbach resonant states are exemplified for some diatomic and a few larger molecules. A special tribute is given to the presently highly active research fields of multipolar electron binding and doubly charged free negative ions.