2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34494General relativity as well as Newtonian gravity admits self-similar solutions due to its scale-invariance. This is a review on these self-similar solutions and their relevance to gravitational collapse. In particular, our attention is mainly paid on the crucial role of self-similar solutions in the critical behavior and attraction in gravitational collapse.14 pages, invited review talk given at the 12th Workshop on General Relativity and Gravitation, Nov 25-28, 2002, Tokyo, JapanGeneral Relativity and Quantum Cosmologytext