What is a Firewall & 4 types of firewalls

Today in this article what is a firewall? what is it used for? And Different types of firewalls You will know about all those topics. The primary purpose of this is to provide security in the computer network.

Nowadays all the people are cautious about the future and on the security side, they get separate life insurance for themselves and family. It is a security in our real life. If the example of real life is taken big celebrities and ministers keep bodyguards for their safety. In the same way, a law has been made for the safety of everyone in the country.

Just as there is a great need for security in our life, in the same way, security is needed to keep the computer and internet safety. You all must know that the Internet is open. In this, everyone keeps on uploading and downloading something.

At that time, various types of viruses and malware are trying to get inside our computers through the Internet. But by blocking all those sites with the help of a firewall, viruses or malware do not enter our system.

What is Firewall in computer?

A firewall is very important in the computer network. It is a device on which you can call hardware, you can say software or you can also say a mixture of hardware and software. It monitors and controls all the incoming and outgoing data packets from the computer.

While accessing the Internet, many popups keep opening on some websites. The software in that popup tries to be installed in our computer which hackers keep operating.

Due to the firewalls, this unwanted software cannot be installed in your system. By blocking all that sites from the firewall, unwanted software does not come into our computers and the system remains safe.

There are some important settings or rules in the firewalls which have to be set by the user. Due to these predefined rules, the firewall can monitor and control the data packets.

For example, the security machine and security person in the airport scans all the bags and catches knives, guns, etc. You can think of it as a firewall. Because it becomes a barrier like firewalls and does not accept unwanted things.

If your computer is connected to a network with other computers and your computer has a virus. Firewalls do not allow these viruses to enter the rest of the connected computer. The firewall of a virus system prevents the virus from entering other systems.

4 Types of firewalls

We use different types of firewalls on our computer networks. 4 major types of firewalls are mentioned below.

Host-based firewall

Host-based means the firewall that is in your system. You can also call it a software-based firewall. You must be using Windows operating system. In the same Windows operating system, there is an option called Firewall inside the Control Panel.

This option will give you all the settings. Generally, we call this software kind of firewall. A computer is a hardware machine in which software is installed and it is working like software.

Network-based firewall

A network-based firewall is a combination of hardware and software that is a dedicated device and has the power to provide security based on the network layer.

It is placed between a private network and the public Internet to filter out harmful data packets coming from the Internet in that network. Where a host-based firewall protects only that computer, a network-based firewall protects the entire network, and any security management defined in it is applied to the entire network to prevent any harmful activity in the entire network. to be stopped before arriving.

A network-based firewall is a hardware device that is mostly installed in large organizations. Nowadays both networks based and host-based firewalls are used in large organizations. In this, a dedicated network-based firewall is used to provide security to the entire network.

A network-based firewall is a hardware device installed mostly in large organizations. Nowadays both network-based and host-based firewalls are used in large organizations.

In this, a dedicated network-based firewall is used to provide security to the entire network. A host-based firewall is there on all the computers on that network. If for some reason malware or virus gets inside the network, then it can be stopped by the host-based firewall. That’s why both firewalls are installed in large organizations.

Packet-filtering firewall

A packet Filter Firewall is used to monitor outgoing and incoming packets. In this, it decides to pass or halt the data packets on the basis of IP addresses, protocols, and ports. This is also called layer 4. Because it works in 4 layers which are the physical layer, datalink layer, network layer, and transport layer. It works up to the transport layer.

In a packet-filtering firewall, the IP header and TCP header are checked regularly. In this, the IP header means to check the IP address and the TCP header means to check the port number.

Packet-filtering firewall

Usually, packet filtering works in the network layer and transport layer. This can block the entire network and a particular IP in it. This means that if any information is coming from that IP address, packet filtering prevents it from coming to its own network.

All rules are allowed in this but the user who does not want to allow them has to be defined within a predefined rule. The one who has to block has to be specified within the rule.

Application-level gateway

This application-level gateway is also called a proxy firewall and it checks the data of the application layer. In the application-level gateway, it can check the header as well as the data. If there is malicious information inside the data, then it can find that malicious information.

In an application-level gateway, data means username or password. If you are using an online booking or payment portal on the internet, then it will ask you for your id and password. All these sites will be HTTPS, which are already secure.

Application-level gateway

When you give your username and password, it goes in encrypted form for further verification. It first goes to the network firewall. Then it checks its IP address and forwards it to the proxy firewall. That encrypted username and password are verified in the proxy firewall.

If that data is correct or it is a valid user, then that IP is allowed to access the database, mail server, or other services. If the information is wrong in the proxy firewall, then it denies that data.

Sometimes you must have seen that some mail in your Gmail goes to Spam. This means that the mail that comes in your mail id, Gmail verifies all the keywords. If it finds a keyword malicious or unwanted, then it begs it in spam.

An example should be taken such that some sites do not open from the system of people who work in the government office. Like YouTube, Facebook, and other non-official sites, etc. This is because the address of all that sites is blocked by the firewall by its network administrator.

Top Firewall Provider Companies


You must have come to know by reading this article how many types of firewalls are in our computer network. If you need more information about the firewall, then you can go to the control panel of your computer and click on the option of the firewall.

I hope all of you have got complete information about what is firewall and 4 major types of firewalls. If you have any doubts about any type of firewall then you can tell us. We will do our best to solve your doubts.

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