Question about Norton 360 Deluxe

That depends on your usage habits. If you are only occasionally on the PC and only ever visit the same pages on the Internet, then you don't need it. Then Windows Defender is sufficient.
However, if you like to experiment with software from dubious sources, then an additional antivirus software can be worthwhile, as it is usually easier and more comprehensive to configure and comes with additional features such as parental controls.

This is antivirus software. :)