Insight and Concentration
A lot of people don't realize that there are really two kinds of Buddhist meditation practice. They should realize it because they are right in the Noble Eightfold Path, Right Mindfulness and Right Concentration.
Some people seem to think that Concentration Meditation is all there is. There are whole branches of Buddhism that don't really practice Insight Meditation.
Here is the difference, as I see it. Concentration Meditation involves focusing on something. Whether that is counting the breath, feeling sensations, or staring at a candle flame, these are all Concentration Meditation. The purpose is to stabilize and strengthen the mind.
Insight Meditation is something different, although the two definitely complement each other. Insight Meditation involves emptying the mind without a point of focus. It involves opening yourself up to experiencing reality as it is, to understanding the nature of things. It is a fundamental part of the Buddha's teaching, but a lot of Buddhists don't even know about it.
Concentration Meditation is very very good. It improves mental and emotional stability, focus, and intellect.
Insight Meditation is the doorway to Enlightenment. It improves our understanding of reality, wisdom, and our control over the three poisons (greed, hatred, and delusion).