What Is a Firewall?
A firewall is a device or software that protects your network, devices and computers against cyberattacks. They are used in both corporate and consumer settings.
Firewalls define a set of rules that dictate what data is allowed through, and what data should be blocked. Every packet of data going through a firewall is inspected and matched against these rules to ensure safe and secure network traffic.
Typically, the data is inspected and checked on the basis of a set of pre-set rules that are specific to your organization’s security policies and needs. Once a packet of data is filtered, it can be allowed into your network or discarded to prevent unauthorized data from passing through your system.
There are many different types of firewalls, with each offering a different set of features that help businesses protect their networks against threats. Here are the most common:
Packet-Filtering: This type of firewall scans all packets and compares them with a list of pre-set rules that determine whether they are allowed through. Typical examples include those that have been reported to be malicious or that contain sensitive information such as credit card numbers and personal health records.
Stateful Inspection: This newer type of firewall does a more thorough examination of all data packets that pass through it. It checks to see if they match up with certain characteristics, such as the source and destination IP addresses, that allow it to know what type of traffic it should be allowing through.