A firewall is a tool used to protect a computer and its network connection from cyber threats. It is a way to filter and control traffic going in and out, in order to protect your system from malicious actors and unauthorized access.

1. Keep your system updated with the most recent security patches.
2. Run regular antivirus and anti-malware scans.
3. Use strong, complex passwords.
4. Keep an eye out for suspicious activity.
5. Install a firewall to protect your network.