The term ''[[firewall (construction)|firewall]]'' originallyoriginaly referred to a wall intended to confine a fire within a line of adjacent buildings.<ref>{{cite book|last1= Canavan|first1=John E.|title=Fundamentals of Network Security|date=2001|publisher=Artech House|___location=Boston, MA|isbn=9781580531764|page=212|edition=1st}}</ref> Later uses refer to similar structures, such as the [[Firewall (engine)|metal sheet]] separating the [[engine]] compartment of a [[vehicle]] or [[aircraft]] from the passenger compartment. The term was applied in the 1980s to network technology<ref name="cheskwick1994">{{cite book | first1 = William R. | last1 = Cheswick | author1-link = William Cheswick | first2= Steven M. | last2= Bellovin | author2-link = Steven M. Bellovin | title = [[Firewalls and Internet Security]]: Repelling The Wily Hacker | year = 1994 | publisher = Addison-Wesley | isbn = 978-0201633573 }}</ref> that emerged when the Internet was fairly new in terms of its global use and connectivity.<ref>{{cite book|last1=Liska|first1=Allan|title=Building an Intelligence-Led Security Program|date=Dec 10, 2014|publisher=Syngress|isbn=978-0128023709|page=3}}</ref> The predecessors to firewalls for network security were [[Router (computing)|routers]] used in the 1980s. Because they already segregated networks, routers could apply filtering to packets crossing them.<ref name="report_unm">{{cite web |url=http://www.cs.unm.edu/~treport/tr/02-12/firewall.pdf |title=A History and Survey of Network Firewalls |year=2002 |last1=Ingham |first1=Kenneth |last2=Forrest |first2=Stephanie |access-date=2011-11-25 |archive-url=https://web.archive.org/web/20060902171316/http://www.cs.unm.edu/~treport/tr/02-12/firewall.pdf |archive-date=2006-09-02 |url-status=dead }}</ref>
Before it was used in real-life computing, the term appeared in [[John Badham|John Badham's]] 1983 computer{{nbh}}hacking movie ''[[WarGames]]'', spoken by the bearded and bespectacled programmer named Paul Richter, which possibly inspired its later use.<ref>{{Cite web|last=Boren|first=Jacob|date=2019-11-24|title=10 Times '80s Sci-Fi Movies Predicted The Future|url=https://screenrant.com/80s-sci-fi-movies-predicted-the-future/|access-date=2021-03-04|website=ScreenRant|language=en-US}}</ref>
