Does Windows Defender need internet access?

Aside from the latest deinitions or updates from M$ does it need an internet connection? There is an option to scan offline but I am wondering if it needs a constant connection for some other reason.

Will there be any adverse reaction due to blocking its connection to the internet?
 


Shouldn't? Guess I will find out definitively. I'll keep it updated the same way I Update everything else, aside from Windows. No reason to auto-update everything. Not something I'd recommend. It's just something I want to do and needed to know whether I was going to break something. Thanks for your time and help SR-71.