Firewall was created to keep all unauthorized things away from private networks. Firewall is one of the first ways to have priate things that are being protected. This could be a software or a hardware, and also can be both. Firewall is supposed to keep all unauthorized internet users from hacking in a private network(s), connected to the internet. This keeps private networks private and so nobody else could get into to it. It is a type of security for your computer; it doesn't allow other users go into your private stash. At any computer you could install this type of security. This allows you to have a secure internet, and it also keeps you way from the public Web and its own internal network. Here are some of the firewall's techniques:

    Stateful Inspection- This tracks the things that are requested by the user.

    Network Address Translation (NAT)- This only allows 1 IP address to refer to many different types of IP addresses. It gives out the translation.

    Packet Filter- This blocks all the Web addresses, or applications that make your computer slow. 

    Application Gateway- This adds the security to overlook such applications.

    Circuit-level Gateway- This applies the security after of when a TCP or a UDP is downloaded.

    Proxy Server- This catches all the messages that are being sent or received from the network.

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