The Hindu Trinity are Brahma, Vishnu, and Shiva. Brahma is the creator of the Universe, Vishnu is the preserver of the Universe and Shiva is the destroyer of the Universe. All three together make the ultimate one Godhead, which has many names. Brahma is not widely worshiped and of all my time in India I only saw one Brahma temple and that was in the sacred town of Pushkar, Rajasthan. Vishnu is widely worshiped. Vishnu is the one Indian God that takes human form and Rama and Krishna are incarnations of Vishnu. Shiva is also widely worshiped and many of the wondering sadus are shiva worshipers.
Hinduism is a monotheistic religion. However, it is understood that by giving God one name or one image or one attribute you are limiting the limitless. Therefore, the Hindus are happy to have many names and images for God because they are able to connect with the infinate through many different paths.