It is a program or hardware device that filters the information coming through an internet connection to a network or computer system.
Answers
The hardware or program that is used for filtering the contents accessing your computer or network through your internet connection is known as Firewall. While it was initially implemented only as a program and software to protect the system, it was later expanded onto portable hardware devices such as USB, disks etc. to make it more widely available.
Firewalls function by examining each and every packet that enters your computer system or network. It even checks on packets attempting to establish a connection. To do this, it overrides the system packet protection service that makes packets immune to examination. By doing this, it is able to ensure that there are no malicious code snippets running on the packet. It also takes preventive measures if it finds such a packet through the internet connection by blocking the site until further instructions are issued.
Firewall is the program or hardware device which filters the information that comes through an internet connection to the computer system or private network.
If firewall finds a flagged incoming packet, then it doesn’t allow the package to deliver to the end users.
But if the filter is broken unwanted dangerous virus can affect your computer system.