So, What's the Difference Between Cacti and Succulents?

So, what's the difference between cacti and succulents?

Here's where people get tripped up, so listen closely: All cacti are succulents, but not all succulents are cacti. Did ya get it? 

Succulents, simply put, are specialized plants that store water in their leaves, roots, or stems. 

Cacti are succulents, but they have spines that come from areoles. Which, by the way, areoles are padlike buds from which spines, shoots and flowers grow from. Only cacti have these.

Here's a picture, for you visual learners out there. 

So, when you see a plant that appears to be a cacti, check for areoles. Like this one: 

This is an Aloe vera succulent. Not a cactus.

This Aloe vera plant has spines and appears to be a cactus to the untrained eye. However, due to the lack of areoles, it is not a cactus.

Ready to try another one? Alright, is the picture below of a cactus or a succulent? (Although, technically all cacti are succulents, so you could potentially say, "Both")

This is Ferocactus gracilis. Definitely a cactus.

You guessed it! (Hopefully) It is a cactus (and a succulent...both). You see those slightly fluffy looking pads that the spines are erupting from? Those are areoles!

Alrighty! I hope that that cleared some things up! Let me know if you have any other questions!

(Also, all photos, except for the very first one, is from google images.)