Final answer:
Bandwidth refers to the capacity of a network to transmit data in a specific period, measured in bits per second, with 75 Mbps being an example of high bandwidth.
Step-by-step explanation:
The total amount of data that can be transmitted in a certain period of time is known as bandwidth. Bandwidth is often measured in bits per second (bps) and is used to indicate the capacity of a network or communication system to transmit data. In the context of the example provided, a wireless router with a transmission rate of 75 Mbps has a bandwidth of 75 million bits per second. This metric is critical when considering the efficiency and speed of data transfer over a network.