Final answer:
A multiplexer combines multiple inputs into a single output, while a de-multiplexer does the opposite by taking a single input and distributing it to multiple outputs.
Step-by-step explanation:
A multiplexer is a digital circuit that selects one of several input signals and forwards it to a single output line based on control signals. It is often used to combine multiple data signals into a single stream. For example, a multiplexer can be used to transmit several different audio signals through a single wire by selecting them one at a time.
On the other hand, a de-multiplexer is the reverse of a multiplexer. It takes a single input line and distributes it to one of several output lines based on control signals. This is commonly used in telecommunications, where a de-multiplexer is used to separate different channels of data that were combined using a multiplexer.
In summary, a multiplexer combines multiple inputs into a single output, while a de-multiplexer does the opposite by taking a single input and distributing it to multiple outputs.