A server is a computer (or computers) that provides storage, information or services to users. This can be in the form of video, email, databases or even just a printing server.
Because of the list of components that can make up an entire server, it is assumed that a server has crashed when any individual component fails, which results in the server failing to operate in its intended fashion.
Typically, though, server failures are the result of failed disk drives, or crashed or failed RAID arrays. Although no longer common, it could be as a result of a failed RAID controller, or the server itself could crash due to memory issues or failure of any other component.
Often mission-critical, server failure is usually serious for a business and downtime can be costly.
