TYPO3 extensions consist of several files. Some of these files have predefined names, and serve a predefined purpose. Others provide code or data but also follow certain naming conventions. We will review all the predefined files in this chapter and see what purpose they serve. We will look into the files according to their logical grouping.
While reading this section, you can take any extension from the
typo3conf/ext/ directory at your TYPO3 installation and check the contents of each discussed file. Some files may be missing if the extension does not use them. There is only one file which is mandatory for any TYPO3 extension,
ext_emconf.php. We will start examining files starting from this one.