TYPO3 is more than just a Content Management System. In its function as a framework, it can be used to develop sophisticated online applications.
As a powerful framework TYPO3 comprises an extensive development frame, in which individual extensions can be developed or core functions of the system accessed.
The TYPO3 core, based on an Apache web server, accesses content stored on an SQL database via PHP and delivers the data. Essentially, it consists of the database model and its access functions in the backend, a directory structure as well as the user and rights management. All additional functions are implemented as extensions in the form of plug-ins or modules. The basic version already contains extensive prefabricated and immediately usable functions. Via the extension API (Application Programming Interface) any number of extensions can in principle be linked with the core.
Thanks to its modular structure, the core is strictly separated from those functionalities that are not part of the normal TYPO3 scope. Newly developed extensions can easily be integrated into TYPO3 by using the extension manager and extension API. These can interact with the T3 core functions via API. In this way, TYPO3 can also be used as a pure framework for the development of complex Web Applications.