There are two forms of electrical signaling done in Ethernets: baseband and broadband. We will consider only the baseband. When a computer wishes to send a stream of bits, its transceiver alters the voltage on the wire using the Manchester encoding system. The change in voltage propagates throughout the length of the copper wire at almost the speed of light, spreading outward in both directions from the position of the transceiver. All other transceivers on this Ethernet will pick up these alterations. Since a message put onto the wire is received by everyone else, we say that Ethernets are broadcast networks.