A **signal** enters a **channel** when it is routed into a structured path for processing, mixing, or output. • **Signals** are raw electrical data representing sound. They exist independently and can carry audio information but are not organized for manipulation or output. • A **channel** is the pathway through which a signal is managed, controlled, or processed. For example: • When a signal enters an input (like a microphone or line-level source) and is routed into a mixer, audio interface, or digital audio workstation (DAW), it becomes part of a **channel**. • A channel provides tools for shaping the signal, such as volume control, EQ, and effects. In essence, a **signal enters a channel** when it passes through a device or system designed to interpret and work with it, transforming the raw data into an audible result.