Why transreceivers is used in communication protocol?

[Bjtpower_magic]

Hello Folks,
Hope you are all doing well.

I am newbie for the Embedded hardware, i have referred few of the communications protocol while surfing
One common thing i have observed that everywhere i can see use of transreceivers.
Can communications-CAN Protocol.
Ethernet-Ethernet PHY (RMII/MII)
RS 485-Isolator

i dont know why they have Used, if we cant use, then what would be causes.

Regards,
DC

 

[danadakk]

Basically they create what is called the physical layer in a communication system. Everything
from low speed single ended, like UART, to high speed differential, LVDS.

Some are electrical, some optical.

They have different properties, solve various problems, are and have been evolving standards
used across multiple platforms, like computer, industrial, automotive.

Physical layer - Wikipedia

en.wikipedia.org

Regards, Dana.

 

[ZASto]

Transceivers are not used in protocol, they are just a way for connecting 2 or more devices physically and have nothing to do with protocol.
Protocol is software implementation of communication between 2 or more devices on a bus.