The difference is cephalopod arms have suckers all the way along their length, but tentacles only have suckers at the end (except for nautilus tentacles, which have no suckers).
Arm:
Tentacle:
So octopus have 8 arms and no tentacles, squid and cuttlefish have 8 arms and 2 tentacles (except female cuttlefish, which have 6 arms), and nautilus have around 90 tentacles and no arms.
Want to learn how to speak bigfin reef squid? Better get your chromatophores in order, because these cephalopods use their color-changing skin cells to communicate!
Anonymous
