Which statement correctly differentiates bandwidth from throughput?

Which statement correctly differentiates bandwidth from throughput?

• A. Bandwidth is the actual rate; Throughput is the maximum capacity.
• B. Throughput equals bandwidth in all cases.
• C. Bandwidth is the latency.
• D. Bandwidth is the maximum data capacity; Throughput is the actual observed rate.

Answer: (D)

The key idea is the difference between what a link can potentially carry and what you actually get in practice. Bandwidth represents the link’s maximum data capacity—the highest rate data could be transferred if everything were perfectly efficient. Throughput is the real amount of data that actually gets through per second, which is typically lower than the theoretical maximum because of protocol overhead, retransmissions, congestion, and other inefficiencies. That’s why the correct statement says bandwidth is the maximum data capacity and throughput is the actual observed rate. For example, a 1 Gbps link has the capacity to carry up to 1 Gbps, but you might observe only, say, 800 Mbps in real traffic due to overhead and network conditions. The other options mix up capacity with actual performance or confuse bandwidth with latency, which is about delay, not rate.

The key idea is the difference between what a link can potentially carry and what you actually get in practice. Bandwidth represents the link’s maximum data capacity—the highest rate data could be transferred if everything were perfectly efficient. Throughput is the real amount of data that actually gets through per second, which is typically lower than the theoretical maximum because of protocol overhead, retransmissions, congestion, and other inefficiencies.

That’s why the correct statement says bandwidth is the maximum data capacity and throughput is the actual observed rate. For example, a 1 Gbps link has the capacity to carry up to 1 Gbps, but you might observe only, say, 800 Mbps in real traffic due to overhead and network conditions. The other options mix up capacity with actual performance or confuse bandwidth with latency, which is about delay, not rate.