This is a question that a lot of people ask so don’t feel daft for not knowing the answer. Now as a product there is very little difference (if any), between cannabis and marijuana. The difference being in the meaning of the words. The differences between the two words are like saying, mate instead of friend or butty instead of sandwich!
Cannabis is the scientific name of the plant, where as, the word marijuana is of Mexican origin, coming from the word marihuana, and is a casual term that has been adopted across the world.
This is the only technical difference, however there are a few sociological differences….
Cannabis is the official name, meaning it is associated with medicine and other official avenues. Cannabis, as a term, is more likely to be used by doctors, botanists or politicians whereas marijuana, being a more casual term, forms a mental picture of rap stars rapping about revenge shootings, and/or stoned teenagers living in their parent’s basements. ‘Cannabis’ is grown in seed banks for official legal use and ‘marijuana’ is grown in basements and back gardens for more illicit uses!!!
These differences show that even though both words have the same meaning, there is a difference in how they are perceived by society. The same product receiving a different title dependent on where and by whom it was cultivated.
It could be argued that quality of product is a defining difference between cannabis and marijuana also. Cannabis being official, therefore, assumed to be of higher quality (and cultivated in a controlled environment), than the unofficial equivalent that is marijuana.
All of this is purely subjective; the only thing that is completely certain is that cannabis is the scientific and official name of the plant whereas marijuana is just a catchy nickname.