A Fusebox 4.1 application consists of Circuits. A circuit
corresponds to the directory of the application. There are one or more
fuseactions in each circuit. A fuseaction is a request handeller. Fuseaction
executes one or more fuses. Fuses are individual CFML pages in ColdFusion.
Fusebox requests are made of the server through a central
controller called index.cfm. This is the central channel through which all
requests pass and that contains several fuseaction methods.
Here, central controller is index.cfm and it receives the
fuseaction message of document.login.
Document is the circuit name and login is the fuseaction