Bandwidth:

“The amount of data that can be transferred through a communication medium at unit time is called bandwidth. It is the measure of transmission rate of communication channel. For analog signals bandwidth is measured in hertz (Hz), for digital signals bandwidth is represented in bits per second.”
Broadband: “It is a communication technique in which signals are transmitted over a transmission medium without changing in modulation, digital signals are called baseband signals, token ring and Ethernet uses baseband signals.”