This document discusses cyclic groups and their properties. It begins by defining a cyclic group as a group that can be generated by one of its elements. It then provides examples of cyclic groups like the integers under addition and groups of integers modulo n. The key properties of cyclic groups are then outlined, including that cyclic groups are abelian, and the criteria for determining subgroup order and generators. Finite cyclic groups are shown to have unique subgroups for each divisor of the group order. The document concludes by discussing the classification and enumeration of subgroups in cyclic groups.