Multiplexer may refer to any of the following:
1. With communication, a multiplexer is a circuit or other device that allows several devices to send data over a single communication line.
2. With computer memory, a multiplexer is a device that helps find a memory address. For example, with a 16-bit multiplexer, a column address of 0101 is the fifth column (0101 in binary is five). Next, another multiplexer would look at the row address of 0001 to know the row address. Once these addresses are known, the memory is found in the memory matrix by going to the fifth column of the first row.