“Succulents” are not their own distinct family, but can be found in around 60 families of plants. Cacti, in the Cactaceae family, make up one of these families. So all cacti are succulents, but not all succulents are cacti. Cacti are simply a subcategory within a group of plants, which are known collectively as succulents. All succulents are defined as water-storing plants. The word “succulent” comes from Latin “sucus,” meaning juice or sap, and the modern word simply means “juicy.”