Firewall
Definition
A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.
Functionality
This system acts as a barrier between a trusted internal network and untrusted external networks, such as the internet. It examines data packets and determines whether to allow them to pass or block them based on a set of defined policies. These policies can be configured to permit or deny traffic based on various criteria, including source and destination IP addresses, port numbers, and application protocols.
Operation
By analyzing traffic, a firewall can prevent unauthorized access to a private network and protect it from malicious software and other cyber threats. It essentially acts as a gatekeeper, enforcing security boundaries.
Example
An example of a firewall's action would be blocking an attempt to connect to a company server from an unknown IP address.
Common Usage
Firewalls are a fundamental component of network security, commonly found in both home and enterprise environments to safeguard data and systems.