Meditation is a technique for producing an altered state of consciousness. It usually involves sitting still for a period during which consciousness might be focused by means of a word repeated silently in the mind, or by the visualization of an image of some sort. The Vipassana, or insight, meditation practiced by Buddhists stresses mere observation of what takes place in the mind and body during meditation.
Meditation in the Bible goes back to the book of Genesis and appears periodically throughout. Focus is not on a word, but on a thought or concept. An example of a verse on meditation is found in Psalms 1:2
But his delight is in the law of the Lord, and on his law he meditates day and night (NIV version).
Christian meditation is a form of silent, contemplative prayer that uses a prayer-word, which is rooted in the gospel and the letters of St. Paul, and originated with the early desert fathers of the fourth century. It is a daily personal discipline, a practice of stillness and simplicity, not a substitute for all the other forms of prayer, but as a center for them.