From About Freemasons
A Grand Lodge, which is called a "Grand Orient" in some Jurisdictions, is the traditional governing body of blue lodges in Freemasonry. Each Grand Lodge governs the craft lodges within a specific jurisdiction. The first Grand Lodge was the Premier Grand Lodge of England, established in England in 1717.
The Grand Lodge is organized much like craft lodges. The head of a Grand Lodge is known as the Grand Master. The names of other Officers of a Grand Lodge are very familiar to anyone who understands the organizational structure of lodges, as the Officers in Grand Lodges add the word "Grand" to their titles. Other than this difference, however, the offices in a craft lodge and Grand Lodge are much the same.
Most Grand Lodges have Jurisdictions that correspond to a specific geographical area. For example, there is a Grand Lodge for every state in the US. Each of these Grand Lodges coves the state in which it has jurisdiction. It is also important to note that each Grand Lodge generally is independent of every other Grand Lodge. The only exception to this is any Grand Lodge that is not recognized by another Grand Lodge. In these cases, a Grand Lodge does not allow its Masons to visit the lodges within the jurisdiction of the Grand Lodge that is not recognized. In most cases, a Grand Lodge chooses not to recognize another Grand Lodge because some violation has allegedly been made of one of the tenants or landmarks of Freemasonry. Recognition can also be somewhat interconnected. For example, Grand Lodges that are recognized by the United Grand Lodge of England (UGLE) are also recognized by all Grand Lodges in amity with UGLE. The opposite is also true. For example, many Grand Lodges recognized by the UGLE do not recognize the Grand Lodges in South America, because the UGLE does not. The one exception to this is the Grand Lodges of the US, which do recognize South American Grand Lodges.
In many countries, there is one Grand Lodge for the entire nation. For example, the UGLE is the Grand Lodge of England. Ireland also has the Grand Lodge of Ireland and Scotland has the Grand Lodge of Scotland to govern over every craft lodge in the country. However, many European countries have more than one Grand Lodge in their countries. The United States has had one mainstream and one Prince hall Grand Lodge per state. Each of the Grand Lodges are independent of the Grand Lodges of every other state. Each of the Grand Lodges in the states are recognized by all the other Grand Lodges of the states, and most recognize the Prince Hall Grand Lodges in every state as well.
It is important to keep in mind that Grand Lodges govern craft lodges or blue lodges. Freemason orders open only to Master Masons -- such orders include The Shriners, for example, and the Scottish Rite -- have their own governing bodies. These governing bodies are not answerable to the Grand Lodges in their jurisdiction. However, some orders that are affiliated with the Masons do defer to the Grand Lodges in their jurisdiction, recognizing the Grand Lodges as the main Masonic authority in their area.
Since Grand Lodges are all independent of each other, there's also no centralized government or body that governs all the Grand Lodges around the world. As a result, Grand Lodges are free to develop their own rituals, policies, and practices. This is one reason why Freemasonry can look significantly different between one area and another. Rather than having one governing body, Grand Lodges are organized by fellowship or cooperation with one another.