Each group is represented by an xml file with the name <group>.xml; for example, css.xml. These files are stored in the config/templates directory that resides in the PhpStorm's user settings directory.
PhpStorm comes with a set of pre-defined groups of live templates. The user group, represented by user.xml file, is intended for storing custom live templates.
It is strongly recommended to avoid storing custom templates in the pre-defined PhpStorm groups. For this purpose, use the user group, or a new group.