Firewall have
Firewall has:-
A firewall is a network security system designed to prevent unauthorized access to or from a private network connected to the Internet, especially intranets. We can implement a firewall in either hardware or software form, or a combination of both.
A firewall is simply a program or hardware device that filters the information coming through the Internet connection into your private network or computer system. If an incoming packet of information is flagged by the filters, it is not allowed through.
An application gateway is an application program that runs on a firewall system between two networks. When a client program establishes a connection to a destination service, it connects to an application gateway, or proxy.