electric circuits - $V$-$I$ linear OR $V=IR$ is statement of Ohm's law?

What is the real statement of Ohm's Law: $V$-$I$ is linear OR $V=IR$?

Looks like V-I is linear is ohm's law and conductors don't alway obey ohm's law and R=V/I is a general definition of R wheather conductor obeys ohm's law or not

Can someone please confirm above.