Answer:
There are many sects, such as Tibetan Buddhism, Zen, Pure land, etc, but all Buddhists typically fall within two traditions. These are Theravada and Mahayana.
Theravada Buddhism is most closely linked to the teachings of The Buddha as written in the Pali texts. The practices of Theravada are typically less focused on rituals, recognize only one Bodhisattva (Maitreya Bodhisattva) , The Buddha (Siddhartha Gautama) and older Buddhas that pre-date him. Because the practice follows only the teachings that came from The Buddha. Theravada is often called the Teachings of the Elders. The goal of a Theravada practitioner is to become an Arhat, a person who attains enlightenment. There is only one school of thought for Theravada.
Mahayana believes that there are, and can be, an infinite number of Buddhas and Bodhisattvas. The number increases as the number of people attain Buddhahood or become a Bodhisattva. Buddhism practiced by a Mahayana has been influenced by local traditions. The goal of a Mahayana practitioner is to achieve either Bodhisattva or Buddhahood in order to help all other beings to become enlightened.
These descriptions are not comprehensive but give a good introduction to the differences.