The Three Gunas are described as the three qualities or ropes which bind. These three qualities are Sattva, Rajas and Tamas.
Sattva refers to a state of balance, order, or purity. It is the balanced midpoint between the states of Rajas and Tamas.
Rajas refers to a state of over activity or turmoil. It is associated with a mind that is constantly seeking diversion and has difficulty focusing the attention.
Tamas refers to a state of lethargy in which the mind is negative, dull, or slow. Usually it is associated with darkness, delusion, or ignorance.