Group Order

Definition 1.4 – Group Order

The order of a group, $\lvert G \rvert$, is the number of elements in the set. For instance, some group $G = \{ g_{0}, g_{1}, g_{2}, \dots, g_{n -1} \}$ has an order $\lvert G \rvert = n$.

The order of a group, and the nature of the elements, distinguishes three kinds of groups.

  1. Finite Group: the order is finite
  2. Discrete Group: the order is infinite, but the elements are countable (e.g. integers)
  3. Infinite Group: the order is infinite