Fernando Ortega’s 750-Word Expanded Definition of Firewall

TO: Prof. Ellis

FROM: Fernando

DATE: 10/4/19

SUBJECT: Expanded Definition of “Firewall”


The importance of this document is to learn about the historical context of a word, the origin of where it came from, and how the word’s definition has changed over time also the accurate definition that is used in the present day. The term that I will be defining will be “Firewall”, I will be providing definitions of the word from the Oxford English dictionary and online sources to analyze the changes it has gone through with the definitions.


The first definition from the Oxford English Dictionary (OED) is “An unbroken line of flames forming a barrier; a wall of fire. Somewhat rare” (“firewall,” 2019). This is definition explains a barrier on fire used for a line of defense that is resistant. Based on the definition, “firewall” was much like a form defense that does not provide enough context on the word. The second definition is, “A wall or partition designed to inhibit or prevent the spread of fire; spec. such a wall in a building, which extends to a certain height above the roof.” (“firewall,” 2019). This talks about a big wall that has the height of a roof used to prevent the spreading of fire from passing over the wall. The third definition is, “Something designed to protect the security or integrity of a system, process, or institution, esp. by acting as a barrier; a measure taken to prevent something undesirable occurring; a safeguard” (“firewall,” 2019). This explains about an object that protects the trust it has with a certain system by preventing harmful things from happening to the system acting as a barrier or safeguard. This definition has a lot of context than the last two definitions by showing that it is designed for protecting a system and preventing unexpected things from happening to the system. The fourth definition is, “A system, typically a piece of hardware or software, which provides protection against unauthorized access to or from a private network or computer system” (“firewall,” 2019). This is a system that is software or hardware that can be used to protect a private network or computer system from anything that does not have permission from accessing them. It has similarities to the last definition with the concept of protecting a system and the difference is the terms to specify what it’s protecting, this last definition uses computer terms such as network and computer. When reading these definitions, all of them have a similar concept of having to protect or preventing something from happening. By using words, like the wall, barrier, protect, or unbroken to signify something that can’t be trespassed easily. From what I have gathered, the first definition is from the 1570s and the definition is vaguely defined as time passes a little more context is added to the definition. Like in definition 1, it just mentions a wall of fire, definition 2, adds more details by adding on what it prevents, definition 3 using more words to describe the definition. In addition, the fourth definition having more computing terms like hardware, software, private network.


The magazine defines firewall as, “These computer firewalls are actually more like fire doors because they have to let some stuff through.” Firewall is much like a door that opens and closes to let things pass through, this is much different from the other definitions since it does not use the terms like barrier or wall. In a blog they mention, “A firewall is a type of cybersecurity tool that is used to filter traffic on a network” in definition they mention how a firewall is a cybersecurity tool and it filters traffic. I would say that this is almost an accurate definition than the one from the magazine because it is relatable to the fourth definition since it uses more computer terms. In another source Alex X. Liu defines it differently, “A firewall is placed at the point of entry between a private network and the outside Internet such that all incoming and outgoing packets have to pass through it” this definition explains how a firewall is in between a network inside and outside of the internet watching packets that pass inside and outside. Another piece of information I would add from this same source is that they explain the function, “The function of a firewall is to examine every incoming or outgoing packet and decide whether to accept or discard it.” Based on this I can tell the definition from the 1570s focuses from a battling point of view different from Alex’s definition because it focuses on a technological view.

Working Definition

Learning about the firewall relates to my major because it has to do with networking & security and having more knowledge of the word helps understands the term in multiple ways other than in the IT terms. My own definition for this term is a protocol that checks for unwanted data from entering a system or host without permission.


Dosal, E., (2019, Sept 12). What is a firewall? The different firewall types & architectures. Retrieved from www.compuquip.com/blog/the-different-types-of-firewall-architectures

firewall, n.,1. (2019). In Oxford English Dictionary Online. Retrieved from http://www.oed.com/view/Entry/249400. Accessed 12 October 2019

firewall, n.,2. (2019). In Oxford English Dictionary Online. Retrieved from http://www.oed.com/view/Entry/249400. Accessed 12 October 2019.

firewall, n.,3. (2019). In Oxford English Dictionary Online. Retrieved from http://www.oed.com/view/Entry/249400. Accessed 12 October 2019.

firewall, n.,4. (2019). In Oxford English Dictionary Online. Retrieved from http://www.oed.com/view/Entry/249400. Accessed 12 October 2019.

Liu, X. A., (2009, Nov 10). Firewall policy verification and troubleshooting. Elsevier, Retrieved from https://www-sciencedirect-com/science/article/pii/S1389128609002199

Tero, and Paul., (2013, Jan 30). A comprehensive guide to firewalls. Smashing magazine, Retrieved from www.smashingmagazine.com/2013/01/introduction-to-firewalls/

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