Built-in antivirus covers the basics, but Shield adds scam site blocking, remote-access protection, and family features it doesn't include.
What this means
The antivirus built into Windows or macOS mainly scans for known viruses. Shield adds AI-powered scam site blocking, protection against the remote-access tools scammers use to take over a computer, and, on Family Lite and Family plans, a Guardian Dashboard and Remote Help for looking after your whole household.