Glossary:Solid State Disk

A Solid State Disk (or SSD) is a faster (though more expensive) alternative to a hard disk for a computer's long term storage. Instead of a spinning magnetic disk, it stores data as trapped electrical charges in silicon chips. With no moving parts, it's much more robust than a hard disk. (It's a strange term in a way as it's no more solid than a hard disk.) See All about SSDs in the Wiki.