What is a firewall, what is it and how does it work?

Firewall, which is among the technical terms that can be heard by even those who are not related to the IT sector, is used to provide network security, as it can be understood from its name, although it means "firewall". Firewall, which can be used for both individual and corporate purposes, is why it is widely known. However, there are many details that can be learned from the importance of the firewall to what it does, from its working principle to its types. Here's what you need to know about the firewall ...

What is a Firewall and How Does It Work?

Firewall or firewall, in its most basic definition, "Security systems produced for computers." It means. Firewall or firewall devices, on the other hand, bring these software together with the appropriate hardware and enable them to work in harmony. The firewall's task; It consists of deciding whether the packets coming to it on the network will go to the places they should reach in accordance with the previously defined rules. The firewall, which allows the passage of packets that comply with the defined rules, prevents the passage of packets that do not comply with the existing rules, thus providing a high level of protection.

While simpler versions of the firewall are available to individual customers, more complex and systematic versions can be developed for companies. 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 internal and external networks based on predetermined principles. This ensures a controlled data flow at all times. In addition, many firewalls can work with a proxy that meets users' request packets before they go to the network.

What is the Importance of a Firewall?

Firewall systems are divided into hardware-based and software-based. A software firewall is usually installed on operating systems on clients and servers. Since they can be installed on a single network and have a simpler structure, they are often preferred for individual purpose home computers. Hardware-based firewall works only with firewall devices and is developed for structures that need more complex network security systems such as companies. Whether software or hardware based; Firewalls are equally important for all systems and play a very valuable task such as threat management in attacks that may come from the Internet.

What are the Firewall Types?

Data and data transfer have become much more complicated since the eighties, when the first simple firewall was developed. This resulted in more advanced firewall types with different features. That's why today there are three basic types of firewalls from three different generations. These; first generation packet filter firewalls, second generation circuit level firewalls and third generation application level firewalls.

Packet Filter Firewalls

Packet filter firewalls, the first generation firewall developed in the eighties through one of the largest technological companies of the period, are referred to by this name because they contain a simple packet filtering technology. Packet filter firewalls, which have become widespread rapidly, have developed with the contributions of large technology companies in the following years and gained features such as blocking of unwanted packets.

Circuit-Level Firewalls

When the first generation firewalls were insufficient as a result of the network traffic that became more complicated with the development of technology, a circuit level firewall, also called the second generation, was developed. Developed in the laboratories of a technology company between 1980 and 1990, the circuit-level firewall was able to control more complex network traffic much healthier and more accurately than the first generation.

Application Level and Proxy Firewalls

Third-generation firewalls, known as application-level or proxy-based firewalls, were developed and launched through a technology company, just like the first generation. Third generation firewalls, which can now filter at the application stage, also brought security to the next level with better filtering feature.