A term for any device that would prevent undesirables on the global Internet from getting at your or your company's network. It also often prevents or controls users from getting out to the Internet from your local network. A combination hardware and software buffer that many companies or organizations have in place between their internal networks and the Internet. A firewall allows only specific kinds of messages from the Internet to flow in and out of the internal network. This protects the internal network from intruders or hackers who might try to use the Internet to break into those systems.
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