One-channel refers to a wireless microphone system that has only one receiver and one transmitter, suitable for solo vlogging, podcasting, and any other content creation that features one person only. Two-channel, or dual-channel, means that there are two transmitters and one receiver in the system. The receiver can capture the signals from both of the transmitters at the same time, making it suitable for interviews, live streaming, short video production, and any other content that involves two people. Three-channel, as indicated by the name, means the receiver can capture and process signals from three transmitters at the same time. Suitable for multi-person interviews, vlogging, and meetings. Four channels refer to a system that contains four transmitters and one receiver. Suitable for stage performance, instrument performance, roadshows, and multi-person interviews.