An introduction to a Firewall is essential for a beginner. The purpose of a Firewall is to act as the first line of defense in network security. You can define a Firewall as a network security system that acts as a barrier between internal network and external sources like the internet to intercept and block data packets that don’t conform to its set of rules.

Firewall meaning, as the name suggests, is that it is a barrier to protect the computer systems and networks from outside attacks. The answer to the question ‘What is a Computer Firewall ?’ is that it is used to secure information from unauthorized users from both within the network and from outside networks. A beginner needs to understand Firewall basic concepts like what is meant by a Firewall or Firewall meaning in a computer.

In this article let us look at:

  1. What is a Firewall
  2. Types of Firewall
  3. Uses of a Firewall
  4. Advantages and Disadvantages of a Firewall
  5. Functions of a Firewall
  6. Features of a Firewall
  7. List of Firewalls

1) What is a Firewall

A simple explanation of what a Firewall is that it is a hardware or software to protect a private computer or a network of computers. This protection is achieved with software or hardware or both to allow only authorized traffic and filter out all unauthorized users from accessing private computers and networks.

A Firewall in a computer is a type of Cybersecurity tool. A Firewall in a computer is used for information security by detecting and blocking out all attempts at unsolicited access. Before venturing further, a beginner has to understand the basics of a Firewall and also know how does a Firewall work. A router in your home is a simple example to answer the query of what is a Firewall with an example. The Firewall in Win 10 is an answer to what is a Firewall in a computer.

2) Types of Firewall

There are several types of Firewalls which can be installed depending on the requirements of the users. We shall explore what are the different types of Firewalls available.

  • Proxy Firewall: This is one of the early types of Firewalls. One of the characteristics of this Firewall is that it prevents direct connection to a computer for outside networks. This Firewall functions for specific applications as a gateway from one network to another.
  • Packet Filtering Firewalls:  This is about the most basic type and this Firewall application is for creating a barrier at the router. The working of the Firewall is only for checking the source and destination IPs without going into packet details. This is a Firewall example of one of the oldest architectures.
  • Circuit level Gateways: This simple Firewall configuration works by checking the transmission control protocol, TCP, handshake to ensure that the packet is from a legitimate source.
  • Stateful Inspection Firewalls: This is a different type of Firewall which combines the above two methods to create a configuration with a higher level of security.
  • Next-Generation Firewalls(NGFW):  As the threats increase, most of the bigger companies are going in for the next-generation Firewalls which provide far greater benefits of a Firewall. These NGFW types come with many high-end capabilities to provide top-end Firewall advantages to large organizations with a higher risk profile.
  • Software Firewalls:  A software Firewall definition is that it is a software installed on a device without any additional hardware. This answers the question of what is a Firewall software as well. Is Windows Firewall enough might be a legitimate doubt regarding stand-alone or individual computers? While windows give some basic protection, the need for firewalls in the form of an anti-virus plus application is always there. 
  • Hardware Firewalls: Hardware Firewalls comprise devices that act as the first line of defense to filter data packets before they arrive at the servers. The major disadvantages of Firewalls of the hardware type are that they are easy for insider attacks to bypass them and the hardware capabilities vary with each supplier.

These are some of the firewalls and their types. The type suitable for an organization has to be chosen after careful consideration of all factors including vulnerabilities.

3) Uses of a Firewall

The uses of a Firewall are numerous. Questions like what is the use of a forewall or what does a Firewall do or what is a Firewall and what is its function are only natural when some big investment is required.

A Firewall and its uses are given below for a better understanding.

  • The useful thing about a Firewall is that it prevents unauthorized remote access and remote control of your computer by a hacker for evil purposes.
  • Data security is ensured based on IP address and protocol.
  • It ensures continuity of operations and availability of information.
  • It blocks destructive or unsuitable or pornographic content.
  • It prevents ransomware, malware, and phishing attacks.
  • It shields older PC with earlier versions of OS.
  • It is safer for online gamers.

The above points explain a Firewall adequately.

Components of a Firewall are packet filtering, application gateways, and logging, and detection of suspicious activities.

4) Advantages and Disadvantages of a Firewall

There are both advantages and disadvantages of a Firewall as is to be expected.

Advantages of Firewall

  •  A Firewall prevents hackers and remote access.
  • It protects data.
  • It ensures better privacy and security.
  • It protects from Trojans.
  • A network-based Firewall, like a router, can offer protection to multiple systems, while an OS-based Firewall can protect individual systems.

Disadvantages of Firewall

  • Cost:  Installation of a Firewall can be costly depending on the sophistication required.
  • Performance: This is affected as each packet has to be verified for authenticity before it is allowed into the network.
  • Virus and Malware: There are a few limitations in a Firewall like its inability to prevent virus and malware attacks for which separate applications would be required, at the individual system level.
  • A network-level Firewall might bring in a false sense of security in employees and make them slacken on securing individual systems. Companies need to make all employees understand the concept of a Firewall and the importance of a Firewall for information security and their responsibility.
  • Firewall maintenance and up-gradation require extra manpower and resources.

5) Functions of a Firewall

The main function of a Firewall is packet filtering. The other function is to act as an application proxy, commonly referred to as an application-level gateway.

Some other functions are Stateful Firewalls which are dynamic, stateless Firewalls, deep packet inspection Firewalls, management functions, and more depending on the role of Firewalls and what is the Firewall security level that is required for a company.

6) Features of a Firewall

A list given below answers the common query What are the features of a Firewall.

  • Bandwidth control and monitoring.
  • Web filtering.
  • Internet aggregation.
  • Sandboxing.
  • VPN, Virtual Private Networks.
  • Deep Packet Inspection, DPI.

7) List of Firewalls

A small list of Firewalls available is provided.

  • Checkpoint
  • Fortinet
  • Watchguard
  • Sophos
  • Forcepoint
  • Juniper
  • D-Link
  • Palo Alto
  • Fortinet


Once issues like what is a Firewall and how it works or how does a Firewall works are clear, then how to create a Firewall for a home computer is easy to implement. It is easy to learn how to use a Firewall like in MS Windows 10 for a personal computer. At this stage, a learner should be able to explain a Firewall and also elaborate on what do you mean by Firewall.

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Also, Read

Firewall Configuration: A Useful 4 Step Guide


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