You encounter these terms in pranic healing, which is an ancient Hindu system of energy healing. Chakra refers to the energy center, while Prana means life energy. Aura is energy that exists along with our physical body.

The aura that covers our body has seven layers pertaining to the physical, emotional, mental, and spiritual aspects as manifested by energy. The color and thickness of aura give ideas on the state of our health. The aura has six colors representing different personalities. All these colors are present within us, but one or two are more pronounced:
Green: ambitious achiever
Blue: spiritual peacemaker
White: unconventional chameleon
Red: activist
Orange: creative communicator
Violet: psychic

On the other hand, Tantra is popularly associated with the practice of sex and spirituality. It comes from the word "tan" which means to spread or expand. The concept of connectedness is a recurring theme in Tantric writings on sex and spirituality.

Tantra presupposes that the union of man and woman can reach spiritual levels during orgasm and this removes the collected impurities within the body and mind. These negative impurities can manifest as physical illnesses.

While Pranic and Tantric healings have Hindu origins, Reiki originated from Japan. It is a relatively new concept as people rediscovered Reiki in the early 1900's.

Reiki stands for universal energy coming from a higher intelligence. Students of Reiki tap this energy to heal physical, emotional, and mental illnesses.

Although Pranic, Tantra, and Reiki are all systems of energy healing, these differ in the type of energy used for healing, namely: life energy, sexual energy, and universal energy.

All three forms of healing are similar in terms of the connectedness of mind, body, and spirit; the connection of individuals to all living and nonliving things and the universe; and how energy impacts physical, emotional, and spiritual well being.

In spite of the availability and relative accessibility of modern medicine, why do people seek alternative methods? Here are some possible reasons:

Energy healing worked where modern medicine failed.
For several reasons, modern medical treatment failed to heal ailments of several people. Because of this, people take the risk of using alternative methods ranging from herbal, organic, faith healing, and New Age techniques just to get well.

Modern medicine's approach leans towards isolation.
Medical treatments focus on the disease and causative agent. A patient feels isolated for he is treated like a mere host of the disease.

Although recent developments in hospital care promote holistic treatment, the perception persists. In energy healing, there is an intimate link between energy and spirituality. The patient feels that alternative healing covers all aspects of his health.

Energy healing is non-invasive and natural thus, it is safer. Repeated surgical procedures are physically and emotionally traumatic. Because of this, patients and their families look for less stressful health interventions. Moreover, with the rising popularity of New Age religions, going natural is the way to go.

Energy healing is a good way of relieving stress.
Meditation, which is a method to relieve stress, is part of energy healing. This is an added come-on for highly stressed people. Moreover, meditation does not require sophisticated equipment and is more convenient for students of energy healing.

The battle between alternative healing and mainstream medicine continues as both methods present various benefits. What is more important is we focus on the bottom line, which is the ultimate restoration of good health.