In a sentence, meditation is an upsurge of the soul, literally the soul rising in action. Spiritual leaders say that the soul is hardly ever a part of our daily life - the only time the soul manifests itself, that too only partially, is when one appreciates a work of art or satisfies an intense hunger, literally for food or for sex or sleep. But how much joy there is in the satisfaction of these hungers! And in the detachment one experiences when one fully appreciates a work of art or looses oneself in literature! It is this joy that is also the aim of meditation besides the removal of the desires for material things or for perfection in our relationships with others which cause so much unhappiness.
Although the senses are the medium of the soul, they hardly ever act in a concerted fashion. Meditation concentrates the senses on a single point which is, initially, concentration on an external point, symbol, image or picture, followed by concentration on an internal point, symbol, image or picture and, finally, concentration on universal existence, the three stages leading the person to an effortless state of perfect concentration. Since the aim is to focus the senses, the first stage is important so that the mind, which is used to animate objects, should not suddenly feel incapable of doing what is required. The next step is concentrating on an image within the mind, which helps in removing one's concentration from the material world and consequently leads to the abstract concentration on universal existence. A difficult concept to understand, universality transcends the limitations set by the body and the mind, leading to a state of pure concentration.
On a more practical level, meditation is ideal for removing the stress and strain of daily life. When one reaches a certain level of concentration, meditation becomes a substitute for satisfying the hungers of the mind and the body. Since according to Indian spiritual leaders control of desire is the key to longevity, meditation has a two-fold impact.
Anything can be meditation so long it is sincere and heartfelt. Chanting mantras is one way. Another is concentrating on the sun. It basically involves constant observation of the mind, which helps you to tap your inner resources for the wisdom, and peace that lie within you.
The first thing a person who wishes to meditate must understand is that meditation is not a duty to be performed or a skill to be learned. It is not the equivalent of cooking or working but since it brings one closer to oneself, it is a part of developing one's own consciousness. It is only in this fashion can one learn to meditate.