Final answer:
Broadband signals use electromagnetic or optical waves to transmit data, utilizing carrier waves that modulate in amplitude or frequency, as opposed to baseband signals which are more limited in scope.
Step-by-step explanation:
The correct answer to the student's question is: Broadband signals move across the medium in the form of electromagnetic or optical waves, rather than baseband signals.
Electromagnetic waves are the foundation for broadcasting communication signals. They can vary in amplitude, frequency, or phase to carry information. For instance, amplitude modulation (AM) and frequency modulation (FM) are common methods that use radio waves to transmit audio signals over various distances. The term carrier wave can be used to describe an electromagnetic wave that transmits information by changing its amplitude or frequency.
Moreover, when we talk about broadband signals, we're often referring to technologies like optical fibers, which employ laser signals to transmit data. Optical fibers have low loss, high bandwidth, and reduced crosstalk, allowing them to transmit more information over longer distances than electrical signals on copper wires. Unlike baseband signals, which are typically used for short-distance communications and send one signal per wire, broadband signals can carry multiple signals at varying frequencies, which is crucial for the Internet and long-distance telephone communications.