What is Firewall and its types ?

Firewall

• prevents unauthorized access to or from a private network
  Common use is to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets.
• can be implemented in both hardware and software, or a combination of both.
• also useful for allowing remote access to a private network through secure authentication certificates and logins.

Working of Firewall

•  All messages entering or leaving the intranet passes through the firewall.
•  Examines each message and blocks those that do not meet the specified security criteria.

Firewalls can be either hardware or software but the ideal firewall configuration will consist of both.

Hardware firewalls

• can be purchased as a stand-alone product
• typically found in broadband routers
• mostly have a minimum of 4 network ports to connect other computers
• for larger networks, business networking firewall solutions are available

Software firewalls

• installed on your computer like any software and you can customize it
• allows some control over its function and protection features
• protects your computer from outside attempts to control or gain access your computer