This thesis reviews the holographic principle. The holographic principle states that the number of degrees of freedom has the bound proportional to the boundary area of the region. It is deduced from the entropy of the black hole. The holographic bound gives the conjecture that we can describe physics in the bulk in which the gravitation act by a theory of one less dimension which can be thought as living on the boundary. AdS/CFT correspondence is the example of the holographic principle. Also using AdS/CFT correspondence, we can confirm that the number of the degrees of freedom of AdS space is proportional to the area of the boundary.
