A general definition of succulents is that they are drought resistant plants in which the leaves, stem or roots have become more than usually fleshy by the development of water-storing tissue.
The storage of water often gives succulent plants a more swollen or fleshy appearance than other plants, a characteristic known as succulence. In addition to succulence, succulent plants variously have other water-saving features, (CAM) to minimise water loss: