Flash vs. SSD Storage: What's the Difference?
When discussing solid state drives (SSDs), many people — even experts — use the terms “flash” and “SSD” interchangeably. It’s an understandable linguistic choice because the two technologies are very closely related. However, the two terms don’t refer to exactly the same thing.
The difference between the two might be easiest to understand with an analogy. And one of the most apt analogies that gets used in the storage industry is that flash is like eggs and an SSD is like an omelet. In the same way that an omelet is made mostly of eggs, an SSD is made mostly of flash. And if someone asked what you had for breakfast, it would be understandable if you answered “eggs,” even if what you really had was an omelet.
Continuing the analogy, you can also do lots of things with eggs besides making omelets. In the same way, you can do lots of things with flash besides making SSDs.
Source: Disaster Recovery Journal