What is the significance of a firewall in a computers security scheme?

Q. What is the significance of a firewall in a computer's security scheme?

Answer:-

An Internet firewall is a device or software that is designed to protect your computer from data and viruses that you do not want. A firewall is so called because of the real firewalls used to secure buildings. A physical firewall is a set of doors that closes in a building so as to contain a fire to one area, preventing the entire building from being destroyed. Likewise an Internet firewall is designed to shut off access to your operating system or to other computers that are connected to your network.