List of available widgets is in the Graphics->Widgets tab. Each of them has a unique name, whose prefix tells us what type of an element we are dealing with.
In order to insert a widget in any place it's best to use the “Widget inserter” guide by clicking the "Widget" button under content or template edition panel. Our guide will allow us to generate a proper code and insert it in a specified place, where the result of our chosen elements work will be displayed.
Example of code looks like this:
{{W name="contentListShow" type="lastest" bucket=390 imageFit="fit" showAuthor="true"}}
Every system code begins and ends with two curly brackets. After that the proper variables are chosen and functions are called out.
The "W" function calls out widgets. It has to contain a "name", which tells you how the widget is called out by the code. The remaining variables are intended solely to be just for the widget and it determines what they're supposed to look like and if they are needed or not.
In the example a widget, which will show us recently added contents from group of pages with ID 390, was called out.