The differences between squid and octopus that I know are:

1. Difference in appearance: Octopus is generally spherical, while squid is bag-shaped.

2. The number of legs is different: octopus has eight legs and squid has 10 legs.

3. The inner shell is different: Octopus has no inner shell, while squid has a relatively developed inner shell.

4. Different attack methods: Octopuses generally use ink to attack each other to help them escape or find food, while squids mainly use "ink jet" as a weapon to escape or catch food.

5. Different IQs: Octopus has a higher IQ than squid.