Firewall

A firewall is a filter that watches network traffic and blocks connections that are not allowed, keeping unwanted visitors away from your device.

Firewall: A firewall is software or hardware that checks the data coming into and leaving a device or network, and blocks what breaks its rules. Think of it as a guard at a gate. It stops many outside attempts to connect, but it cannot stop you from willingly installing a bad program.

Home Wi-Fi routers contain a basic firewall that hides your devices from the open internet. Windows and macOS also include one, and it should stay on. A firewall helps most against unwanted outside connections, such as scans of open services on a computer or camera. Business servers use stronger firewalls that also watch for suspicious patterns, but the idea is the same: allow only what is needed.

It does little against threats you invite, like a fake app, a phishing link or a trojan attachment. Also, a router with the default password can let an attacker simply turn the firewall off. Keep the built-in firewall on, update the router, and do not open ports for remote access unless you know exactly why. On phones, a similar filtering role is done by a DNS filter or a network security tool.

Tips

• Keep the Windows or macOS firewall switched on at all times.
• Change the router's default admin password and turn off remote administration if you do not need it.
• Do not rely on a firewall alone; also avoid unknown links and files.

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