Other names of Shiva: Mahadeva, Shankar, Shambhu, Mahesh, Neelkantha, Bholanath, KailasPati, UmaPati, Rudra, Ishaan, Ishwara, and hundreds more.
Other forms of Shiva: Shiva-Linga, Nataraj, Ardha-Nareeshwara, Dakshinamurti
Significance: Shiva is one of the three main aspects of the Supreme/Divine, the other two being Brahma and Vishnu. Shiva means auspiciousness. Shiva represents the principle of dissolution. Everything in the universe that has a name or a form is perishable. Shiva is the original cause /process working that makes dissolution possible. Due to this, He at times is incorrectly referred to as the God of destruction. Dissolution is a necessary process for creation.
Shiva is depicted in a sitting, meditative pose, or in a family setting with consort Parvati and sons Ganesh and Kartikeya and surrounded by Nandi (bull), and Ganas. Shiva is the God with utter simplicity and austerity. His clothes, his decorations, his abode are minimal. He has a simple deer or tiger skin as his clothes, sacred ash (vibhuti) smeared on the body, long hair tied together in a knot, snakes around the neck and His arms are decorated. He is an embodiment of Tapas, Vairagya, and Knowledge. He is always meditating on the welfare of the Universe. What do all of these mean to us?
Ganga symbolizes Chid-Shakti (pure consciousness, wisdom) or knowledge flowing from heaven to earth. She comes down to Earth through Shiva (auspiciousness). Wisdom descends only through the medium of auspiciousness. The crescent moon symbolizes complete control over mind and the third eye, which is usually closed, symbolizes pure knowledge which burns away all dualities when opened. Sacred ash on the body signifies spiritual wealth left over after dissolution of all worldly desires. The blue neck of Shiva points to His extreme compassion for the world. He is holding poison in the neck and not completely swallowing it.
Trishula (trident) shows that he is beyond three Gunas (Sattva, Rajas, Tamas), beyond three states of consciousness, and beyond past, present and future. Beats of damaroo (drum) sets the cosmic rhythm by which the universe maintains its dynamic harmony and balance. The snake is a representation of Kundalini Shakti (mystic spiritual energy) and also represents a poisonous animal. Shiva is immune to its poison. Nandi (bull) is a vehicle of Shiva and signifies Dharma as well as pure Ananda (joy). Tiger skin represents slain ego (ahankar) and control over all lower nature.
In the form of Dakshinamurti, Shiva is a universal teacher who imparts knowledge by silence. In the form of Nataraj, dancing Shiva represents the cosmic laws of the dynamic universe-a universe continuously in motion but not out of balance. In the form of Ardha-Nareeshwara, Shiva represents simultaneously both male and female principles working together to manifest the universe. In the form of Linga, Shiva is depicted as form-less, feature-less ultimate reality, the Self who is fully absorbed in his own self. There are twelve famous and ancient Jyotir-linga spread across India.
There is an ancient saying: Shivam bhutva Shivam Yajet, which can be generally translated as "meditate on Shiva to become like Shiva". In the famous Shloka of 'Shiva Mansa Pooja' connection of Shiva to ourselves is made clear: My own Atman is Shiva, my own pure buddhi is Parvati, my own Prana is nothing but Ganas, and my own Body is Shiva's abode… and therefore whatever I do let it be an offering of pooja to Shiva (my own Atman). An image of Shiva once understood in its true sense, can be a source of great inspiration for all to improve themselves.