Meditation is a state, often defined as deep dreamless sleep awake. But, in the same way that you cannot sleep on demand, you cannot meditate on demand—that is, you can’t reach the state instantly in the same way that you can raise your right hand. The practices preceding meditation are relaxation, stillness and mental focus. Those are all things you can do. They are the preparation. Then, if you the circumstances are right, you can transition from the waking to the meditative state.

Concentration is… a relaxed mental state, where the stream of consciousness flows in a single direction, either focusing on a phrase or mental picture, or alternately, a state in which the mind is alert and aware.

Whether one is remaining alert (mindfulness), focusing on a single thought or phrase (mantra), or mentally exploring ones inner world (visualization), all are one form of concentration or another.

Concentration is the doorway through which the meditative state becomes available.

Concentration is the key to success in anything in life. You need concentration to carry on a conversation, to raise children, to stay positive, to be able to communicate effectively, to succeed academically, to meditate, to succeed in business, to become good at sports, to achieve the goals you set for yourself, and the list can go on and on.