There are four noble truths according to the teaching of Buddha: 1) Existence is suffering, 2) Suffering arises from desire, 3) Suffering ends when desire ends, and 4) The way to end desire is to follow the 8-fold path to Nirvana--"Right Belief," "Right Resolve," "Right Speech," "Right Conduct," "Right Occupation," "Right Effort," "Right Contemplation," and "Right Ecstasy".
Kamala is the first of the eight-fold path to Nirvana... "Right Belief". Siddhartha enters the town where Kamala lives with the "belief" that life must be experienced through thoughts and senses. In this way, one truly lives and becomes one with all other creation. From Kamala, Siddhartha learns about love and about other people. She is the first woman he had spoken with in a very long time, having spent years in the forest as a Samana. She taught him about love, she arranged his meeting with Kamaswami, the richest merchant in town who will give him a job and become his teacher in monetary aspects. Through his encounter with her, he leaves his past self behind and learns about the material world...the world of love, of making money, of doing business with others. This is the beginning of his path to Nirvana. From her, he moves through the other seven of the 8-fold path.