An IP logger is a device that records every action taken by computer you have it installed on. They usually log the internet traffic, users’ keywords and phrases, external connections made to your machine, emails sent out from your account to others and all information you type into the keyboard of the device.
When used with an updated firewall set up in active mode, these devices can be a way to monitor misuse of a system or help protect that system from attack. However if not used correctly they often cause more harmful events as they are not monitored for any changes done to them once their set up is complete. There are SO many software logs out there now that offer similar functions without needing this level of hardware compatibility (IP forwarding), however these come at a price that most cannot afford. Also these have the added risk of being hacked into which defeats their use, where as an IP logger can be programmed not to accept any outside interference.