What is a Firewall?
A firewall is a network security device or software that monitors and controls incoming and outgoing network traffic based on predefined security rules. Its main purpose is to block unauthorized access while permitting legitimate communication.
Types of Firewalls:
- Network Firewalls: Protect an entire network by filtering traffic at the router or gateway level.
- Host-Based Firewalls: Installed on individual devices to protect them from malicious traffic.
- Application Firewalls: Monitor and filter traffic specific to certain applications.
- Next-Generation Firewalls (NGFW): Combine traditional firewall functions with intrusion prevention, application awareness, and deep packet inspection.
Firewalls are an essential part of a layered security strategy, preventing attacks such as unauthorized access, malware propagation, and data exfiltration.