Please HELP !

Question

Im trying to make my website responsive for others devices but what confuse me is :
@media (max-width: ) {}
@media screen and (max-width: ) {}
@media only screen and (max-width: ) {}

i want to know if these make different ?

THANKS FOR YOUR ANSWRES .

Answer 1

I found a quite nice answer to your question on StackOverflow: http://stackoverflow.com/a/8595600/6801193

Answer 2

thanks a lot