Joomla Extension Development, A basic bare-bones Module
Module files and folders are located in joomlas/modules folder. Each modules has its own folder named mod_filename" of the module.
For this example we will create a folder named "mod_foo"
the modules folder contains a minimum of 2 files. 1 .php file and 1 .xml file with the same name as the sub-folder.
mod_foo.php and mod_foo.xml