Application programming interface. The published methods for using a set of programs. In Joomla, the API refers to the public methods and fields of all the defined classes, especially ones in the Joomla platform. Because third-party programs rely on the API, it should be changed as infrequently as possible and always with advanced notice.
To change the background click on the label bar and in the layer window select the style tab.
Choose a source from the background top tab then upload an image or pick a background color.





