Transfinite refers to quantities that are larger than any finite number but still part of the mathematical framework. This concept is primarily associated with Georg Cantor, who developed the theory of infinite sets. In this context, transfinite numbers help to compare different sizes of infinity, such as the set of natural numbers versus the set of real numbers. There are two main types of transfinite numbers: transfinite cardinals and transfinite ordinals. Transfinite cardinals measure the size of sets, while transfinite ordinals describe the order type of well-ordered sets. Both concepts are essential in understanding the structure of infinite sets in set theory.