We are used to firewalls in other disciplines, and, in fact, the term did not originate with the Internet.  
The first network firewalls appeared in the late 1980s and were routers used to separate a network into smaller LANs. 
be
Firewalls like this were put in place to limit problems from one LAN spilling over and affecting the whole network. 
Brian Reid and the engineering team at DEC's Network Systems Lab in Palo Alto originally invented the DEC firewall. 
During the next few months, Marcus Ranum at Digital developed security proxies and rewrote much of the rest of the firewall code. 
rewrite
In this same time frame, Cheswick and Bellovin at Bell Labs experimented with circuit relay-based firewalls. 
Raptor Eagle came out about six months after DEC SEAL was first delivered followed by the ANS InterLock. 
be first delivered
Check Point introduced icons, colors, and a mouse-driven, X11 based configuration and management interface, greatly simplifying firewall installation and administration. 
Over the years, we have added to this list of ¨requirements¨ access to the World Wide Web, live news broadcasts, weather information, stock quotes, music on demand, audio and videoconferencing, database access, file sharing, and the list goes on. 
No matter what the base technology, a firewall has always acted as a controlled gateway between two or more networks through which all traffic must pass. 
Although VPNs were available before firewalls via encrypting modems and routers, they came into common use running on firewalls. 
come
In the past two years, it has become popular for firewalls to also act as content screening devices. 
Recently, some firewall and router vendors have made the case for a relatively new firewall add-on called ¨flow control¨ to deliver Quality of Service (QoS). 
In 1997, The Meta Group, and others, predicted that firewalls would be the center of network and internetwork security. 
Actually, firewalls have become synonymous with security. 
As the use of the Internet and internetworked computers has continued to grow ever since, so has the use of Internet firewalls.