There are many types of flash, and it can be installed in many places. This has led to some confusion surrounding terms such as flash memory, solid-state disk (SSD), and solid-state storage. There is an “assumption gap” in which some people understand flash, but others do not really know what it means. This brief is intended to be educational in nature, and is designed to convey the basics of flash technology. It explains the flash formats that exist today, and provides a high-level guide to the relative costs and performance of different types of flash.