A firewall monitors incoming and outgoing network traffic and blocks or allows data based on a set of security rules. It acts as a barrier between a trusted internal network and untrusted external networks.
Key points
Definition:Firewall: a security system that scans incoming and outgoing network traffic and allows or blocks data based on predefined security rules.
Can block traffic from suspicious IP addresses or stop certain types of data from entering the network.
Helps protect against DoS attacks and malware from the Internet.
Can be hardware-based (a physical device) or software-based (a program running on a computer).
Exam Tip:A firewall FILTERS traffic based on rules — it does not detect malware by signature like anti-malware software does.