what is the difference between eth1 and eno1?

eth1 is the onboard Ethernet (wired) adapter on your Linux machine.

eno1 is your embedded NIC (onboard Network Interface Card). It is a regular physical network interface.

You can use this link as reference.

This is a way of representing the Ethernet names. If machine has already eth1 in its config file for the second adapter it will use eno1 rather than using eth2.

They both are same. Its just a name of config file. You can also change the name eno1 to eth2 by doing a simple Google search.

Here is the link for changing the same: Click