Networks refer to the interconnection of devices, such as computers, servers, and other devices, through a communication medium, such as cables, Wi-Fi, or cellular networks. Security services, on the other hand, refer to a range of techniques and technologies used to protect computer networks and their associated resources from unauthorized access, use, disclosure, disruption, modification, or destruction.

Some common network security services include:

1. Firewall: A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

2. Virtual Private Network (VPN): A VPN is a network security service that allows users to securely access a private network over a public network, such as the internet.

3. Intrusion Detection and Prevention System (IDPS): An IDPS is a network security system that monitors network traffic for signs of intrusion and takes action to prevent attacks.

4. Antivirus and Anti-Malware: These are software programs designed to detect, prevent, and remove malicious software, such as viruses, worms, and spyware, from a computer or network.

5. Data Encryption: Data encryption is a security service that converts plain text into ciphertext to protect sensitive data from unauthorized access.

6. Access Control: Access control is a security service that restricts access to network resources based on predefined policies and permissions.

7. Network Monitoring: Network monitoring is a security service that involves the continuous monitoring of network traffic for suspicious activities and threats.

These are just a few examples of the many network security services available to protect computer networks and their associated resources.