They are software or hardware systems that control incoming and outgoing data traffic on your servers, network infrastructure and personal computers, allowing or preventing data passage according to determined filtering policies. The firewall, which protects the network within the company or the computers on the networks against attacks from the internet, controls the network traffic between the internal and external networks based on predetermined principles. This ensures a controlled data flow at all times.
Different types of firewalls have software, hardware, or a combination of both. All of them have different areas of use, strengths and weaknesses.
Among the most common firewalls used; Stateful firewall. Allows or blocks traffic based on technical characteristics such as specific protocols, states, or ports. Stateful firewalls make filtering decisions to determine whether to allow data to pass through to the user. These decisions are usually based on rules set by the administrator when installing the computer and firewall. The firewall also makes its own decisions based on previous interactions it "learns".
Proxy firewalls are the closest form of protection to a real physical barrier. Unlike other types of firewalls, a proxy acts as an intermediary between external networks and computers, preventing direct communication between the two.
Next-generation firewalls keep this problem under control by combining the features of a traditional firewall with network intrusion prevention systems. They are designed to further investigate and detect specific threats such as advanced malware. Mainly Used by advanced networks, these firewalls provide a holistic solution to filter out threats.