Footers are a secondary element in a web page because they usually appear at the bottom and it is the last thing that the user interacts with. But the presence of the footer must be designed in every application and be part of it (consumer or back-office) as it is a key layout element to the overall experience. It is a choice of the designer to either leave the footer visible by default or push it down, depending on the use case.
The footer is part of the application layout, so it can only be used inside of it. Please check the DxcApplicationLayout documentation.
The footer component has a custom area where many kinds of content can be placed, some of them are contemplated in the following list:
Menu links
Forms
Actions