Final answer:
Medical marijuana is prescribed by doctors for the treatment of health conditions, while street weed is used for recreational purposes with no medical prescription.
Step-by-step explanation:
The main difference between medical and street weed is the purpose for which it is used and the regulation surrounding it. Medical marijuana is marijuana that is prescribed by a doctor for the treatment of a health condition. It is used to help with certain medical problems and is legal in over half of the United States. Street weed, on the other hand, is marijuana that is bought and used for recreational purposes and has no medical prescription or oversight.