Security is often a matter of trust. People are very wary of installing anything new, anything that's not from a reputable brand and, for good reason.
Microsoft has been supplying Windows Defender with Windows for years. This has migrated into a reputable anti-malware suite and we've known Mac users who wish Apple would offer something similar for their Mac. Although Mac's are less likely to suffer from malicious software, it's not unknown, especially downloading new software from third party websites.
Now there's a way to install Microsoft's Windows Defender on your Mac, officially, courtesy of Google Chrome. Well, a very limited version. Windows Defender Browser Protection is a plugin you can install in all editions of Chrome (Windows and Linux inclusive) and it will sit in the background and monitor the types of websites you are visiting. If you click on a site which it deems as malicious or the potential of being malicious, you will be warned. Malicious websites are taken from an expanding list held by Microsoft.
You're not limited to websites, either. Click on a malicious link within your email client and usually, it will open in your web browser, but the Windows Defender Browser Protection plugin will warn you before it opens and prevent you from a phishing attack via email.
And that's about it. You don't get anti-malware protection or any other security module such as a firewall, parental controls or a password manager. This isn't a replacement for a security suite.
Very simple browser add-on that uses a known Microsoft malicious website list to stop you from accidentally browsing a dodgy website or phishing email link.