The basic principle of Calvinism is the sovereignty of God. This represents the purpose of the Triune God as absolute and unconditional, independent of the whole fine creation, and originating solely in the eternal counsel of His will. He appoints the course of nature and directs the course of history down to the minutest details. His decrees therefore are eternal, unchangeable, holy, wise, and sovereign. They are represented in the Bible as being the basis of the divine foreknowledge of all future events, and not conditioned by that foreknowledge or by anything originating in the events themselves. (The Reformed Faith by Loraine Boettner.)

It is most often recognized by the acronym TULIP.

T - Total depravity (or inability)
U - Unconditional election
L - Limited atonement
I - Irresistible grace
P - Perseverance of the saints