What Is a Firewall?
Firewall is a term used to describe a variety of devices — both software and hardware — meant to keep cyber attacks from attacking network devices or networks. Firewalls are a key part of your overall security strategy, but they need to be properly configured and updated to be effective against emerging threats.
A firewall works like a gatekeeper at a doorway, examining incoming data packets and deciding to allow or reject them based on pre-established security rules. The rules are based on several aspects of the data packets, including their source and destination addresses, protocols and content.
Using these rules, a firewall can identify and block the most common types of network traffic and malicious code. The resulting filtering process makes it much harder for hackers to gain access to your system and cause security breaches and damage.
While firewalls are a great way to control how external and internal network data is transferred, modern network perimeters have grown so complex that stronger security methods are required at the host level, which led to the creation of Next-Generation Firewalls (NGFWs). These devices use multiple layers of defense, combining traditional firewall capabilities with advanced application awareness and an intrusion prevention system (IPS) to assess traffic on both the host and application layer.
A host-based firewall is a software program that’s installed on individual computer systems. It reads and filters data traffic at the individual user level to detect malicious activity. It also has the ability to prevent direct connections between an internal host network and the internet and limit access to specific websites, IP addresses or applications.