anti-virus/firewall protection

It is “different”, but less “different” than it used to be. MalwareBytes is one of the few antivirus apps that only scans your Mac for Mac malware. The other ones tend to spend most of their time, and your CPU power, checking for Windows malware.

macOS already provides multiple layers of malware protection built into the operating system. It doesn’t provide great protection against “grey market” software like adware. MalwareBytes is good at finding and removing adware. If you sign up for the paid service, it can even protect you against adware. If you find yourself repeatedly getting tricked into installing the latest Flash Player or video codec, then MalwareBytes would be a good value.

Do not install third party antivirus apps. MalwareBytes is different and is often used to find and remove malware.

Effective defenses against malware and ot… - Apple Community

https://discussions.apple.com/thread/6418635?answerId=26198310022#26198310022