A selector can be:

• a DNA probe used in the selector-technique (used in molecular diagnostics)
• a reggae disc jockey (who selects music to play)
• a switch used to choose which function a device will perform
• a special kind of switch used in computers to connect multiple lines (I/O) to a single line. A related component is the multiplexor. Both components are used in the execution of conditional logic such as memory addressing and device selection and signaling.