Electronic switches are a broad category that encompasses any device that controls the passing of signals from any number of input ports to any number of output ports. These signals can be analog or digital.
The digital bus switch is perhaps the simplest of switches. When the switch is enabled, it passes the digital state from its input to its output. When the switch is disabled, the output is in a high-impedance state (open). A slightly more complicated switch is the multiplexer (also known as mux). A mux has multiple inputs of which one is selected and passed to the output. A multiplexer can be analog or digital. The crosspoint switch has multiple outputs and can be programmed to arbitrarily assign any of its inputs to any of its outputs.
Muxes and crosspoints operate on layer 1 of the Open Systems Interconnection (OSI) model. Devices such as an Ethernet switch or a PCIe switch are digital and help steer the data packets across a network to a destination node.