THE THREE GODS of TANTRA
In Hinduism, the Trimurti (also called the Hindu trinity) are the three aspects of God namely:

Brahma - the Creator
Vishnu - the Maintainer
Shiva - the Destroyer

BRAHMA
Brahma is the Hindu creator god, and one of the Trimurti, the others being Vishnu and Shiva. According to Puranas he is self-born (without mother) in the lotus which grows from the navel of Vishnu at the beginning of the universe. However, being the Creator, all of his "sons" are "manas-putras", or mind-sons, indicating their birth from Brahma's mind and not from his body. Brahma only occasionally interferes in the affairs of the gods, and even more rarely in mortal affairs.

Brahma is an agent of Brahman, the Supreme Being or Absolute of Hinduism.

Brahma is traditionally depicted with four heads and four faces and four arms. Each head recites one of the four Vedas. He is usually depicted with a (white) beard and the four arms holding a scepter, a (lota) water-pot used in creating life, a string of beads used to keep track of the Universe's time, the text of the Vedas, and a lotus flower.

The acquiring of Brahma's heads makes for an interesting legend. When Brahma was creating the universe, he made a female deity known as Shatarupa (one with a hundred beautiful forms). Brahma was immediately infatuated. Shatarupa moved in various directions to avoid the gaze of Brahma. But wherever she went, Brahma developed a head. Thus, Brahma developed five heads, one on each side and one above the others. In order to control Brahma, Shiva cut off the top head.

Also, Shiva felt that Shatarupa was Brahma's daughter, being created by him. Therefore, Shiva determined, it was wrong for Brahma to become obsessed with her. He directed that there be no proper worship in India for the "unholy" Brahma. Thus, only Vishnu and Shiva continue to be worshipped, while Brahma is almost totally ignored. Ever since the incident, Brahma has been reciting the four Vedas in his attempt at repentance.

Another legend of the lack of worship of Brahma is as follows: Once, both Vishnu and Brahma approached Shiva and requested to find his beginning and end. Vishnu was appointed the end, and Brahma the beginning. Each took their journey, and neither could find their appointed destination. Vishnu, satisfied, came up to Siva and bowed down to him as a swarupa of Brahman. Brahma did not give up so easily. As he was going up, he saw a kaitha flower, dear to Siva. His ego forced him to ask the flower to bear false witness of Brahma's finding Shiva's beginning. When Brahma told his tale, Shiva, the all-knowing, was angered by the former's ego. Shiva thus cursed him that no being in the three worlds will worship him.

SHIVA
Shiva is commonly known as "the destroyer." Additionally, Shiva can also mean, "the Auspicious One." He is often depicted as the husband of Uma. In the process of creation, Lord Shiva is the primeval being and creates the other members of the trimurti. He is symbolized by the wisdom of the Serpent.

Shiva is the third form of God as the Destroyer, one of the trimurti (popularly called the "Hindu trinity"). In the trimurti, Shiva is the destroyer, while Brahma and Vishnu are creator and preserver, respectively. However, even though he represents destruction, he is viewed as a positive force (The Destroyer of Evil), since creation follows destruction.

According to the Bhagavata Purana, Lord Shiva appeared from the forehead of Lord Brahma. When Lord Brahma asked his sons, the Four Kumaras, to go forth and create progeny in the universe, they refused. This angered Lord Brahma and in his anger a child appeared from his forehead, which split into two - a male part and a female part. The male half started crying inconsolable and as a result, Brahma named him Rudra. This male child became Lord Shiva, who was asked to go forth and create progeny, but when Lord Brahma observed the power, as they shared the qualities of Lord Shiva, he asked him to observe austerities instead of creating progeny.

As Nataraja, Shiva is the Lord of the Dance, and also symbolises the dance of the Universe/Nature, with all its delicately balanced heavenly bodies and natural laws which complement and balance each other. At times, he is also symbolized as doing his great dance of destruction, called Tandava at the time of pralaya, or dissolution of the universe at the end of every Kalpa.

Although he is defined as a destroyer (or rather recreator), Shiva, along with Vishnu, is considered the most benevolent God. One of his names is "Aashutosh", he who is easy to please, or, he who gives a lot in return for a little.

Traditionally, unlike Vishnu, Shiva does not have any avatars. However, several persons have been claimed as embodiments of him, such as Adi Shankara. Some people consider Hanuman to be an aspect of Shiva. Shiva is an aspect of God or Saguna Brahman, (i.e. God with form) who Hindus pray to. In trimurti concept, he is the aspect of God (i.e., God as the Destroyer) of the trimurti (also called the Hindu Trinity), along with Brahma and Vishnu.

Shiva is an icon of masculinity. In mythology and folklore, he can be interpreted to inspire masculine characteristics of the most extreme: absolute virility and fertility (even thought he is infertile himself); aggression, rage and supreme powers in war; his resolve, meditation is absolute, as is his love for his wife, Uma.

VISHNU
Vishnu is a form of God, to whom Hindus pray. Vishnu is the Deity worshipped in the Vedas and their scriptural adjuncts; according to Vaishnavas, He is the Supreme Lord, and is the only entity primarily praised in all true scriptures. Vishnu is the Lord, is the Cause, the Protector, and the Destroyer of all Creation known and unknown, and is responsible for all bondage and liberation. He is beyond the scope of all that is destructible and indestructible, and His worship is the purpose of one's existence; He is free of all flaws, and has an infinite number of good attributes.

For Vaishnavas, He is the only Ultimate Reality or God, as is Shiva for Shaivites. In Trimurti belief, He is the second aspect of God in the Trimurti (also called the Hindu Trinity), along with Brahma and Shiva.

Known as the Preserver, He is most famously identified with His avatars, or incarnations of God, most especially Krishna and Rama. Additionally, another important name for Vishnu is Narayana.

Vishnu has no particular material form but can be manifest in any form, whether animate or inanimate. According to Vaishnava belief, He is the center of all forces, power, will, auspiciousness, goodness, beauty, grace, responsiveness, etc. In short, whatever we can think of, and whatever we cannot think of -- all are Vishnu.

The Rigveda says: Vishnu can travel in three strides. The first stride is the Earth. The second stride is the visible sky. The third stride cannot be seen by men and is the heaven where the gods and the righteous dead live.

Vishnu is always to be depicted holding the four attributes associated with him, being:
  • A conch shell or Shankhya, named "Panchajanya", held by the lower right hand, which represents creativity. The sound that evolves from blowing this conch is the primeval sound of creation.
  • The chakra, a sharp-spinning discus-like weapon, named "Sudarshana", held by the upper right hand, which symbolizes the mind. The chakra as a weapon thus indicates the necessity of destroying one's ego and illusory self-existence and developing the vision to identify the eternal truth.
  • A mace or Gada, named "Kaumodaki", held by the lower left hand, which represents individual existence. The mace symbolizes the primeval force from which all mental and physical strength is derived.
  • A lotus flower or Padma, held by the upper left hand, which represents liberation or dispersion. The lotus symbolizes the power from which the universe emerges.

- all content taken from www.wikipedia.org