There are four paths of yoga that all lead to the same destination, union the Brahman/God/ the creator. The paths are suited for different personalities and natures of spiritual aspirants. Karma Yoga, Bhakti Yoga, Raja Yoga, Juana Yoga are the four main paths of yoga.
The path of yoga that most of us yogis in the US are familiar with is Raja Yoga. This path of yoga is often referred to the Royal Path or the meditation path. Raja Yoga is appropriate for the mystical or scientifically minded individual. The eight limbs of this particular path are all steps to control the mind and body. Asanas or physical postures are a limb of this 8 limbed path that most of us are familiar with. It is a great reminder that the asanas are only a portion of the Raja Yoga practice.
Karma Yoga is suited for the active and outgoing individual. Its focus is on the selfless service of others. By focusing totally on the service of others in the right attitude without care of the outcome, the spiritual aspirant can rid themselves of ego.
Bhakti Yoga is the yoga of devotion and divine love. This path is appealing to those who are emotional in nature. Through prayer, worship and ritual the devotee focuses their practice on channeling divine love and whole-hearted devotion to God.
Juana Yoga is the yoga of wisdom and intellect. It is the most difficult path and the other paths need to be followed before the aspirant takes on the Juana Yoga path. This path requires a tremendous amount of intellect as one will study the scriptures thoroughly and use the mind to inquire the nature of ones own existence.
In the past, all paths could be focused on separately. In modern times the path of synthesis is recommended. The path of synthesis is the combination of all four paths. For example the spiritual aspirant will practice asanas and meditation, serve the less fortunate, study religious scriptures, and participate in group chanting. All four paths will be practiced simultaneously thus, moving the aspirant down the path towards the union with God.