In computers, solid-state device is a term used to describe a storage media that does not involve magnetic disks or any moving parts. For example, computer RAM (random access memory) uses solid-state media. RAM consists of microchips that store data on non-moving components, providing for fast retrieval of that data. Other good examples of solid-state devices are the flash drive and the solid-state drive or, SSD.
What was the first solid-state device?
The transistor is considered to be the first widely used solid-state device and is still being used in almost all electronic devices today.