In Buddhism, meditation means 'resting effortlessly in what is.' This state can be attained by calming and sustaining the mind, through the cultivation of compassion and wisdom, or by working with the body's energetic channels and meditating on Buddha aspects of energy and light.
The most effective method is identifying with one's own Buddha nature, a method taught in the Diamond Way. When the unity between the one who sees, what is seen, and the act of seeing remains intact (both during meditation and between meditation sessions), the goal of the Great Seal is achieved.
The tool that enables us to reach the state where the nature of mind is recognized is meditation. This mental state possesses three characteristics: active compassion, absence of fear, and spontaneous happiness.