Weed, cannabis, pot or marijuana: what’s the difference?

Dispensary employee
A dispensary worker in Washington handles dried cannabis flower. With the plant set to be legalised for recreational use in Canada in summer 2018, the words people use to talk about are more important than ever, according to David Bienenstock, author of ‘How to Smoke Pot (Properly): A Highbrow Guide to Getting High.’

Ganja. Dope. Cheeba. 420. There are lots of names for cannabis. Which is correct?