Meditation is a mind that is single-pointedly focus on a virtuous object and whose function is to make the mind peaceful and calm.
We want to be happy all the time, even during the sleep. How can we do this?, We can do this through training meditation because meditation makes our mind peaceful
When our mind is peaceful we are happy all the time, even if our external condition are poor. On the other hand, when our mind is not peaceful we are not happy, even if our external conditions are excellent. We can understand this though our Owen experience. Since the actual method to make our mind peaceful is training in meditation, we should apply effort to this training. Whenever we meditate, we are performing an action or karma that causes us to experience peace of mind in the future. From this we can understand the importance of training in meditation.
The difference between concentration and meditation is that concentration is necessary a mental factor but meditation can be either a mental factor or primary mind. We can understand the meaning of primary mind and mental factor, the object of concentration can be anything, but he object of meditation is necessary a virtuous object. Wherever an object is virtuous or non-virtous depends on our position. For exemplar, when our enemy harms us and we practice patience , our enemy is our virtuous object, the object of our patience, but if instead we get angry with him he is our non-virtous object, the object of our anger. So it is our choice whether someone or something is our virtuous object or non-virtous object. We should learn to use all living beings as our virtuous objects, the objects of our compassion and patience, and all phenomena as the objects of our training in emptiness.