This question has many answers depending on who you ask and is widely open to interpretation. As you deepen your practice, you may come to find some resonate more than others or you find a unique significance to you.
108 has long been considered a sacred number in Hinduism and yoga. Traditionally, malas, or garlands of prayer beads, come as a string of 108 beads which an additional "guru bead" that is usually slightly larger, around which the other 108 beads turn like the planets orbiting the sun.
Renowned mathematicians of Vedic culture viewed 108 as a number of the wholeness of existence. This number also connects the Sun, Moon, and Earth: The average distance of the Sun and the Moon to Earth is 108 times their respective diameters. Such phenomena have given rise to many examples of ritual significance.
According to yogic tradition, there are 108 pithas, or sacred sites, throughout India. And there are also 108 Upanishads and 108 marma points, or sacred places of the body.