Firewalls 

What it is?

A firewall is a software program designed to control easy access to your network from an outside network. This program is also designed to protect the network from hackers trying to get into the network. It helps secure systems from unauthorized intrusions.

What it does?                         

A firewall acts as a defining perimeter. It protects against hackers and intruders by controlling who has access in and out of your network.  This program also monitors and records that access to ensure that no one illegal comes into the system.

How it works?

A firewall filters data entered into the network. The system then reacts to this data by accepting or denying request to communicate with several application and machines, keeping a log file and prompting if something illegal is coming in. It also authorizes users from getting into the system. If the intruder tries getting in then he or she gets a prompt.

What it doesn’t do?

A firewall would be useless if users share passwords. This is especially risky if users share passwords, as they may be able to get into the server, which leaves the computer the computer insecure

What would happen if you do not have one?

Lack of firewalls in the network makes the network vulnerable and exposes the computer to viruses and hacker attacks.