# Difference between revisions of "Isomorphism"

 This is an AoPSWiki Word of the Week for March 12-19

An isomorphism is a bijective homomorphism. If $A$ and $B$ are structures of a certain species such that there exists an isomorphism $A\to B$, then $A$ and $B$ are said to be isomorphic structures of that species. Informally speaking, two isomorphic structures can be considered as two superficially different versions of the same structure.