Firewalls are essential network security devices that filter traffic based on defined rules, protecting networks from unauthorized access. Various types of firewalls include proxy, stateful inspection, unified threat management, next-generation, and threat-focused firewalls, each serving distinct functions in enhancing security. Firewalls defend against external threats, safeguard internal networks, and help prevent the spread of malware by blocking harmful connections.

1. Network security
A firewall is a network security device that screens approaching
and active network traffic and chooses whether to permit or
block explicit traffic dependent on a defined set of security
rules. Firewalls have been the first line of protection in network
security for more than 25 years. They set up a boundary among
verified and controlled inner networks that can be trusted and
untrusted outside networks, for example, the Internet. A firewall
can be hardware, software, or both.
There are several types of firewalls such as:
Proxy firewall; An early sort of firewall gadget, a proxy
firewall serves as the gateway from one system then onto the
next for a particular application. Proxy servers can give extra
usefulness, for example, content storing and security by keeping
direct connections from outside the system.
Stateful inspection firewall; Presently thought of as a
"customary" firewall, a stateful inspection firewall permits or
blocks traffic dependent on the state, port, and protocol. It
screens all activity from the opening of a connection until it is
shut.
Unified threat management (UTM) firewall; An UTM device
normally join, in an inexactly coupled way, the elements of a
stateful inspection firewall with intrusion prevention and
antivirus.
Next-generation firewall (NGFW); Firewalls have developed
past straightforward packet sifting and stateful inspection. Most
organizations are conveying next-generation firewalls to block

2. modern dangers, for example progressed malware and
application-layer attacks.
threat-focused NGFW; These firewalls incorporate every one of
the capacities of a conventional NGFW and furthermore give
propelled threat detection and remediation.
In its relevance to the network security, firewall plays the
following roles:
Gives defense against outside dangers by declining unapproved
connections to the router from potential attackers, for example,
hackers.
It additionally shields the network infrastructure from inside. In
other words, it blocks active connections from the router. It
mitigates the spread of viruses, keyloggers, or malware that
have sneaked past the router and on the network. Such
malicious software may transmit confidential information back
to the hacker, for example, passwords. Just a firewall can keep
them from doing such by hindering their connection.
References
William R. Cheswick, Steven M. Bellovin, Aviel D. Rubin
(2003). "Google Books Link". Firewalls and Internet Security:
repelling the wily hacker
o 500-700 word, double spaced, written in APA format, showing
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o Prepare a 15 presentation on your final topic
project

3. Policy:
Describing the technology for defeating DDOS attacks would be
a great presentation.
o 500-700 word, double spaced, written in APA format, showing
sources and a bibliography
o Prepare a 15 presentation on your final topic