Here's quantum's definition of S.M.A.R.T. :
"The S.M.A.R.T.1 Self-Monitoring, Analysis and Reporting Technology System was designed precisely with this approach in mind. By using S.M.A.R.T. technology, virtually any intelligent component or device within a computer can communicate its predicted reliability status to its user and system administrator to provide comprehensive protection that can prevent system downtime, productivity loss, and even the loss of valuable data.
Since user data is not always as easy to replace as hardware devices, most computer users will argue that their data is the most valuable element of their computer system. In recognizing the need to elevate the protection of user data, Quantum has pioneered the implementation of the S.M.A.R.T. System for hard disk drives.
Through the S.M.A.R.T. System, Quantum disk drives incorporate a suite of advanced diagnostics that monitor the internal operations of a drive and provide an early warning for many types of potential problems. If detected, the drive can be scheduled for replacement before the loss of data occurs. The result: higher productivity and increased security of data. "