Q: What is the Scottish Rite?
A: The Ancient and Accepted Scottish Rite of Freemasonry (the Northern Masonic Jurisdiction in the United States often omits the and), commonly known as simply the Scottish Rite, is one of several Rites of the worldwide fraternity known as Freemasonry. A Rite is a series of progressive degrees that are conferred by various Masonic organizations or bodies, each of which operates under the control of its own central authority. In the Scottish Rite the central authority is called a Supreme Council.
The thirty-three degrees of the Scottish Rite are conferred by several controlling bodies. The first of these is the Craft Lodge which confers the Entered Apprentice, Fellowcraft, and Master Mason degrees. Craft lodges operate under the authority of Grand Lodges, not the Scottish Rite. Although most lodges throughout the English-speaking world do not confer the Scottish Rite versions of the first three degrees, there are a handful of lodges in New Orleans and in several other major cities that have traditionally conferred the Scottish Rite version of these degrees. 
The Scottish Rite is one of the appendant bodies of Freemasonry that a Master Mason may join for further exposure to the principles of Freemasonry. In England and some other countries, while the Scottish Rite is not accorded official recognition by the Grand Lodge, there is no prohibition against a Freemason electing to join it. In the United States, however, the Scottish Rite is officially recognized by Grand Lodges as an extension of the degrees of Freemasonry. The Scottish Rite builds upon the ethical teachings and philosophy offered in the craft lodge, or Blue Lodge, through dramatic presentation of the individual degrees.