Module
Modules represent discrete types of archaeological record keeping. A module will always have its own unique series of Items which generally corresponds to a Register. Each module has its own settings file which enables it to have a unique set of forms and subforms which may include custom PHP scripts.
Modules are modular in the sense that a given instance of ARK may use different combinations of modules according to the needs of the project. Some modules are really so key to the basic functioning of ARK that they are hard to do without, but never the less they follow the same rules as all other modules. A good example of such a module is the Address Book module, without which much of the system wont work.
To allow greater flexibility in recording and display to users, Modtypes allow records within the same module to contain slightly different information.