Meditation has many forms as there are styles. Praying, contemplating, concentrating, reflecting, observing, pondering, introspection, going into a trance, reciting a mantra, repeating affirmations, journeying through guided or solo visualizations, gazing at a mandala, and even deep sleep all fall under the general definition of Meditation. But for our purpose here, I am referring to the form of meditation universally considered to be its highest expression, I call it Divine Meditation --contemplation and union with the Divine, within and without.
You know it by different names: bhāvanā or dhyāna (Buddhism/Hinduism), Contemplative Prayer (Christian), hitbodedut (Judaism), Zazen (Japanese Buddhism), hesychasm (Greek Orthodox), Dhikr (Islam), Yoga Nidra (Hinduism), Tamarkoz (Sufi), Preksha (Jainism), simran (Sikhism), Neidan (Daoism), Trancendental Meditation, Silva Mind Control, and a few others. Although the individual styles and approaches (not to mention the theology) of these meditation techniques differ from one another, they all seek 'oneness' with the Divine. As they say, there are many roads but there is only one destination (as there is only one God).
Divine Meditation, no matter what method or style you prefer, aligns your spirit/energy body to its highest configuration and gives you access to the resources of the Cosmos. The benefits you gain from constantly communing with the Divine are immeasurable. Physical and Mental well-being are just the tip of the iceberg. Spiritual Oneness and intimacy with God (the Infinite) are the real blessings you will reap. I cannot even put into words what wonders you will gain. Divine Meditation is the essence of real prayer. Practice Divine Meditation in any form and you will be healthy-- in body, in mind, in spirit and in Soul.
"Meditation has been laid stress upon by all religions. The meditative state of mind is declared by the Yogis to be the highest state in which the mind exists. When the mind is studying the external object, it gets identified with it, loses itself. To use the simile of the old Indian philosopher: the soul of man is like a piece of crystal, but it takes the colour of whatever is near it. Whatever the soul touches ... it has to take its colour. That is the difficulty. That constitutes the bondage." -- Swami Vivekananda