Which of the following best defines an endpoint in a network?

An endpoint in a network is best defined as a computing device that interacts with the network. This encompasses a wide range of devices, including computers, smartphones, tablets, printers, and any other devices that connect to the network to send or receive data. Endpoints are crucial because they represent the points at which users access the network and its resources, thereby becoming potential targets for security threats. Understanding endpoints is vital for implementing effective network security measures, as they are often the front lines in the battle against cyber attacks.

The other choices describe important aspects of network infrastructure or management, but they do not capture the essence of what an endpoint is. A central database server is part of the network's backend architecture but does not fit the definition of an endpoint, which focuses on user-accessible devices. A software program that manages network traffic does not represent a physical device that interacts directly with users, while a physical connection point for the network refers to hardware such as switches or routers rather than the endpoints themselves.