Lord Vishnu did his job of preserving the world by incarnating himself in different forms at times of crisis. The three Lords that rule the world have consorts and they are goddesses too. Shiva's consort is Parvati who is worshipped as Kali or Durga. Besides these Gods and Goddesses there are a number of other Gods and Goddesses. The Hindus call their Goddesses 'Ma' meaning mother.
Some gods have more than one name.
Shiva is also known as Shankar, Mahadev, Natraj, Mahesh and many other names. Ganesh is also called Ganpati. God Vishnu incarnated 9 times to do his job and in his every appearance he had a different form which are also worshipped as Gods. Among his appearances, he appeared as Rama, Krishna, Narsimha, Parsuram and Buddha. He also has other titles with meanings like 'Basuri Wala' which means the flute musician and 'Makhan Chor' which means the butter stealer.