Yes it is the same protocol. (Minor revisions change details, jumbo frames etc)
The cables form the physical connection, on that Ethernet defines a way to determine who may send a message (essentially anybody can send while quiet, and if a conflict is detected everybody retries after a random time)
The big thing which changed is that we are often using switched networks, instead of all nodes attaching to the same cable, but that's a change in a higher layer.
Ethernet Designers where smart not tontine the spec to properties of a specific material for transport, but abstract ether where signals travel.
The cables form the physical connection, on that Ethernet defines a way to determine who may send a message (essentially anybody can send while quiet, and if a conflict is detected everybody retries after a random time)
The big thing which changed is that we are often using switched networks, instead of all nodes attaching to the same cable, but that's a change in a higher layer.
Ethernet Designers where smart not tontine the spec to properties of a specific material for transport, but abstract ether where signals travel.