Mind is defined in Buddhism as a non-physical phenomenon which perceives, thinks, recognises, experiences and reacts to the environment.
The mind is described as having two main aspects: clarity and knowing; meaning that the mind is clear, formless and allows for objects to arise in it, and that the mind is knowing, an awareness, a consciousness which can engage with objects.
"What is the mind? It is a phenonmenon that is not body, not substantial, has no form, no shape, no color, but, like a mirror, can clearly reflect objects."
Lama Zopa Rinpoche
The two main types of mind are explained as the conceptual and the non-conceptual. The conceptual is the "normal" mind aspect we use to survive in daily life, but is ultimately mistaken about the way in which reality exists. The non-conceptual type of mind is also called the Buddha nature, rigpa (Tib.), fundamental pure nature of mind which realises emptiness