What is a Firewall?
A firewall protects networks and devices from hackers, viruses, malware, different kinds of cyber threats and attacks. A firewall stands like a guard between your internal systems like computers, servers and devices and the outside world —like the internet or other networks—and carefully inspects data as it comes in and out. This is done by examining data packets (small chunks of information) and comparing them to predefined rules before letting them through.
Different types of firewalls have varying levels of granularity in their rules. For instance, a firewall may look at multiple aspects of a data packet, such as its source, destination, and content to make decisions about whether it can be allowed through or not. Then, it may also record blocked or suspicious activity for security teams to review and investigate.
In order to effectively defend against a cyberattack, network administrators must consider all aspects of their infrastructure and determine the appropriate type of hardware firewall that is right for their organization. This includes considering the number of entry points in a network, and if they operate within a multi-cloud, hybrid cloud or virtual data center environment.
Firewalls can be either hardware or software-based, and are usually inserted inline across a network connection to establish a border between the protected network and external sources. They examine data as it comes in and out of the network and compare it to a set of rules, which are designed to identify malicious data.