A firewall is a computer security measure that separates an internal network from the external network. It is a software application or hardware device that monitors and controls the incoming and outgoing traffic on a computer system.
A firewall is designed to protect a computer system by blocking unauthorized access to the computer system and its resources. A firewall can help protect an organization against attacks from the Internet, other networks, and intruders.
There are a number of factors to consider when deciding whether or not to install a firewall. These factors include the type of network, the type of computer systems, the level of security required, and the budget.
Firewalls can be classified according to the type of traffic they protect. There are four main types of firewalls: network, application, host-based, and device-based.
Network firewalls protect computers on a network by blocking unauthorized access to the network. They can be installed on the network perimeter or at designated points inside the network.
Application firewalls protect applications by blocking unauthorized access to the applications. They can be installed on internal or external computers.
Host-based firewalls protect computers by blocking unauthorized access to the files and programs on the computers.
Device-based firewalls protect devices by blocking unauthorized access to the devices. They can be installed on computers or on network devices.
