There are several types of Cycles that numerologists study. The most important of them are the Period Cycles, which are approximately 27 years each, or three cycles of 9 years.
The first Period Cycle describes how you learn to cope with the world, finding your way around and learning how to deal with other people. During this time, you are also learning to cope with society as a whole, as well as finding your place in life.
The second Period Cycle talks about the emergence of your creative and management abilities and skills, and shows how a degree of control over your situation in the world is developed.
The third Period Cycle represents the emergence of the inner self. Personal power is cultivated and emerges, and reaches its height, along with self-expression and the opportunity to pass on the gift of experience to others.