In a typical Hindu temple, we do not find just one image. We find multiple images. For many people, unfamiliar with Hindu tradition, this looks like polytheism. But for Hindus, these are various manifestations or expressions of the same divine principle. Broadly there are three categories of Hinduism, Shaivism, Vaishnavism, and Shaktism, and so three categories of temples.

Shaivism deals with the hermit, Shiva, who becomes a householder. We always see the image of the hermit with his wife and two sons: Karthikeya, who makes us feel secure, and Ganesha, who nourishes us. So, our hunger and fear are taken care of by the two sons of Shiva. That is the Shiv parivar.