There are a great many different “jurisdictions” of Freemasonry, each independent of the others - there is thus no world-wide central Masonic authority. Masonic Jurisdictions are usually defined by state (as is the case in the United States) or national boundaries. Masons follow some basic rules, or “ancient landmarks” that define, at a basic level, what a Mason is and his duties, though even these are not universally accepted.
Freemasonry is often said to consist of two different branches: the Anglo and the Continental traditions. In reality, there is no tidy way to split jurisdictions into distinct camps like this. For instance, jurisdiction A might recognize B, which recognizes C, which does not recognize A. In addition, the geographical territory of one jurisdiction may overlap with another’s, which may affect their relations, for purely territorial reasons. In other cases, one jurisdiction may overlook irregularities in another due simply to a desire to maintain friendly relations. Also, a jurisdiction may be formally affiliated with one tradition, while maintaining informal ties with the other. For all these reasons, labels like “Anglo” and “Continental” must be taken only as rough indicators, not as any kind of clear designation.
The ruling authority of a Masonic jurisdiction is usually called a Grand Lodge, or sometimes a Grand Orient. These normally correspond to a single country, although their territory can be broader or narrower than that. (In North America, each state and province has its own Grand Lodge.) The oldest jurisdiction in the Anglo branch of Freemasonry is the Grand Lodge of England (GLE) (the Moderns), founded in 1717. This later became the United Grand Lodge of England (UGLE) when it joined with another English Grand Lodge (the Antients) in 1813. It is today the largest jurisdiction in England, and generally considered to be the oldest in the world. Its headquarters are at Freemasons Hall, Great Queen Street, London. The oldest in the Continental branch, and the largest jurisdiction in France, is the Grand Orient de France (GOdF), founded in 1728. At one time, the Anglo and Continental branches recognized each other, but most jurisdictions cut off formal relations with the GOdF around the time it started unreservedly admitting atheists, in 1877. In most Latin countries, and in Belgium, the French style of Freemasonry predominates. The rest of the world, accounting for the bulk of Freemasonry, tends to follow the English lead.
Freemasonry is associated with several “appendant bodies”, such as the Scottish Rite, the York Rite, and the Ancient Arabic Order of the Nobles of the Mystic Shrine (Shriners), among numerous others, all of which claim to expand on the teachings of Freemasonry–often with additional higher degrees–while improving their members and society as a whole.
There are also certain youth organizations (mainly North American), which are associated with Freemasonry, but are not necessarily Masonic, such as the Order of DeMolay (for boys aged 12-21) and the Job’s Daughters (for girls of similar ages).