How does an internet Firewall work?

A firewall works a security gate for the computer. When it is installed it allows certain information to pass through it if that information is safe and trusted and blocks it if the information is not trusted.

How a firewall keeps the information in and out of the computer?

• Every website in the internet carries a signature and carries the information in packets.
• The data coded in these packets is either trusted or distrusted by the firewall, depending on the firewall.
• If the packets are trusted then the information is allowed to access the network  and if the packets are not trusted then the information is blocked.