Use the noun throughput to talk about how fast communication can travel over a channel, from input to output.
For a computer system, the input is the information you enter, and the output is the information that is produced by the program. Throughput refers to how much output is being produced relative to the input. A system could send information at 50 bits per second of throughput, or 500 bits per minute. Throughput is a measure of how fast and efficient the program is, and maximum throughput is often called "bandwidth."