The Four Margas or Paths of Yoga...

Theory
According to advaita vedanta, the goal of life is to discover our true nature. It is usually called self realization or God realization.

Although this goal, our final destination, is one, there are many ways to reach it. People have different temperaments and accordingly, there are different techniques, yogas, to help them find the truth.

The truth is one but the paths are many.
Swami Vishnu-devanandaAnalogy of the Summit
To better understand the concept you can picture a mountain with a summit. The peak of the mountain represents the spiritual goal, moksha. Now imagine there are four people standing on each side of the mountain. To reach the summit, the same destination, each person has to walk a different direction. Likewise, each of us symbolically stands at a different space, spiritually speaking, according to our temperament and personality, so each of us needs to take a customized path to the top.



Four Margas or Paths
From the explanation above, it is easily understood that, truly, there are as many paths as there are people. Practically though, there are a few hundreds of yogas, or practices which are categorized into the four main paths. These paths are:

Jnana Yoga
The path of wisdom and knowledge. The jnani uses his will and power of discrimination to cut through the veil of ignorance and attain the truth.

For the jnani, the goal is absolute Truth.

Jnana Yoga appeals to the philosophical and intellectual temperament.

Bhakti Yoga
The path of love and devotion. The bhakta uses the combined energies of all emotions and transmutes them, sublimates them into the highest of all emotions: prem.

Prem is pure, conditionless, divine love. For the bhakta, or devotee, the goal is pure love.

Bhakti Yoga appeals to the emotional temperament.

Raja Yoga
The path of self control and self mastery. The raja yogi controls his mind until it becomes perfectly still at which time there is no more wall between himself and his own divine nature.

The main practice in Raja Yoga is meditation. For the raja yogi, the goal is perfect mind control.

Raja Yoga appeals to the mystical and scientific temperament.

Karma Yoga
The path of selfless service. For the karma yogi, the main problem is our inherent selfishness which is based on spiritual ignorance, avidya. The key is to practice selfless actions without any selfish expectations, and thereby opening one's heart and seeing God in all beings.

For the karma yogi, the goal is complete selflessness.

Karma Yoga appeals to the active temperament.

Two More for Good Measure
Among the additional hundred yogas out there, two more stand out as particulary important:

Kundalini Yoga
Derived from the tantric tradition this yoga aims at purifying the physical and psychic systems, and then awakening the cosmic power residing in the muladhara chakra at the base of the spine.

Upon awakening and raising of this spiritual power it unites with the consciousness center in the crown of the head and thereby grants liberation to the spiritual aspirant and practitoner of Kundalini Yoga .

Hatha Yoga
Sometimes called the physical aspect of yoga it works mostly on the psychic level. Besides its innumerable medical benefits, hatha yoga is essential support to both raja yoga and kundalini yoga.

from yoga108.org