ELI5: Explain Like I'm 5

Protocol-based intrusion detection system

A protocol-based intrusion detection system helps keep your computer and data safe from attackers. It monitors all the data that go in and out of your computer - this is known as the network traffic. It looks for any unusual activity that might be coming from someone who is trying to get unauthorized access to your computer. If it finds something suspicious, it will alert you so you can take action to protect your information.