Mahayana Buddhism breaks the mind into eight separate consciousnesses. Chögyam Trungpa Rinpoche said the point of meditation is actually to understand how the eight conciousnesses work, because together they create our samsaric reality. They are also the working basis of enlightenment.
1 through 6: The Sense Consciousnesses
The first 5 are familiar: the eye, ear, nose, tongue, and body consciousnesses. They work with our sense organs and objects of perception to create our experience of the phenomenal world. The 6th sense consciousness, called mind, assembles the input from the other sense consciousnesses into a coherent whole.
7: The Klesha or Deluded Consciousness
The 7th consciousness is the home of our concepts, opinions, and inner discursiveness. Sometimes called the “nuisance consciousness,” it is a source of suffering and a place where we spend far too much of our mental time.
8: The Alaya-Vijnana or Base Consciousness
The alaya is the basis and instigator of all our mental activity. It is where we plant our karmic seeds, so it is also called the storehouse consciousness. As the ground of our experience of dualistic reality, alaya is marked by basic ignorance, which can be transformed into wisdom through advanced meditation techniques.