Which of the following best describes 'throughput'?

Throughput refers to the actual rate at which data is successfully transmitted over a network. It takes into account various factors such as network congestion, signal quality, and protocol overhead, which can all affect the efficiency of data transmission. Unlike theoretical measures like bandwidth, which indicate the maximum potential capacity of a connection, throughput focuses on the real-world performance and the amount of data that can be effectively delivered over the network in a given timeframe. This makes throughput a critical metric for evaluating network performance, as it provides a more accurate picture of how well the network operates under actual conditions.

In contrast, other options address different aspects of network performance. The maximum data capacity of a connection pertains to bandwidth, which does not reflect the efficiency or performance in real scenarios. The speed at which data is sent can be misleading if it doesn’t account for successful delivery. The total number of devices connected does not directly tie into throughput, as it doesn't reflect the rate at which data is transmitted.