There is no set definition for any of these terms, and different advocates and politicians will use some of them, particularly legalization and decriminalization, interchangeably in a way that can be very confusing.

But here’s a broad overview of what these three categories are generally taken to mean:

• Marijuana legalization: Legalization is generally taken to represent the removal of all government-enforced penalties for possessing and using marijuana. In most, but not all, cases, legalization also paves the way for the legal sales and home-growing of marijuana.
• Marijuana decriminalization: Decriminalization generally eliminates jail or prison time for limited possession of marijuana, but some other penalties remain in place, treating a minor marijuana offense more like a minor traffic violation. Those caught possessing or selling an amount within the decriminalized limits are still fined — usually no more than a few hundred dollars. States with stricter decriminalization laws can also attach some jail or prison time to possessing larger amounts of marijuana, sales, or trafficking.
• Medical marijuana: Medical legalization lets doctors recommend marijuana for a variety of conditions, from pain to nausea to inflammatory bowel disease to PTSD. A review of the evidence from the National Academies of Sciences, Engineering, and Medicine found little evidence for pot’s ability to treat health conditions outside chronic pain, chemotherapy-induced nausea and vomiting, and patient-reported multiple sclerosis spasticity symptoms. But most states, relying largely on anecdotal evidence, have allowed medical marijuana for many other conditions. And in a few states, medical cannabis laws have been so lax that they may as well be full legalization.

These three categories don’t cover the full array of options for marijuana reform, with a 2015 report by RAND listing a dozen alternatives to the standard prohibition of pot. Among the possibilities: legalizing possession but not sales (as DC and Vermont have done), putting state agencies in charge of sales (as some Canadian provinces are doing, and as some states do, successfully, with alcohol), allowing only nonprofit organizations to sell pot, or permitting only a handful of closely monitored for-profit companies to take part.