Which notation distinction is correct for data storage versus throughput?

• A. Data storage uses capital B and throughput uses lowercase b
• B. Data storage uses lowercase b and throughput uses capital B
• C. Both use uppercase B
• D. Both use lowercase b

Answer: (A)

Distinguishing bytes from bits is what this tests: data storage quantities are described in bytes, so we use an uppercase B to denote bytes. Throughput or data rate is described in bits per second, so we use a lowercase b to denote bits. The reason is practical: storage capacity uses bytes (KB, MB, GB), while network speeds are about how many bits per second can move, so they’re expressed as bits per second (Mbps, Gbps). Since one byte equals eight bits, you can relate the two by dividing by eight. For example, a 100 Mbps link transfers 100 million bits each second, which is about 12.5 million bytes per second (12.5 MB/s).