Technology
How does a firewall work?
A firewall works as a security guard for a network, deciding which data is allowed in or out based on a set of rules. It inspects incoming and outgoing traffic and blocks anything that looks unauthorized or dangerous.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how a firewall works.
Step by step
- 1It sits between a trusted network and the outside internet.
- 2It checks data packets against allow/deny rules.
- 3It blocks unauthorized access while letting safe traffic through.
- 4It can filter by address, port, or application.
- 5It's a first line of defense, often paired with other security.
Frequently asked questions
- What does a firewall do?
- It monitors network traffic and allows or blocks it based on security rules, keeping out unauthorized or malicious connections.
- Is a firewall enough to stay safe?
- It's an important first layer, but real security also needs updates, antivirus, strong passwords, and careful user behavior.
- What's the difference between hardware and software firewalls?
- A hardware firewall protects a whole network from one device; a software firewall runs on an individual computer to guard just that machine.