What does network latency refer to?

Network latency refers specifically to the delay that occurs before a transfer of data begins after an instruction has been sent. It is a crucial metric in networking that affects the overall responsiveness of applications and services. When a user sends a request, network latency measures the time taken for that request to reach its destination and for the response to begin returning. High latency can lead to noticeable delays in interaction, such as in online gaming, video conferencing, or browsing.

In contrast, the other options focus on different aspects of network performance. The overall speed of the network encompasses both bandwidth (the amount of data that can be transmitted) and latency, but it does not specifically define the delay aspect. The capability to handle multiple tasks relates to parallel processing and resource management rather than latency itself. The time taken for packets to be encrypted pertains to security protocols and does not reflect latency, which is strictly about the delay in data transfer initiation. Thus, option B correctly identifies network latency as the delay before data transfer begins following an instruction, making it the precise definition in this context.