16 - Input, Output and Storage GapFill

 PrimarySecondaryRAMROM storage is an essential component for any device that must maintain a store of data even when the system has no power.  Such storage keeps its contents intact without power, unlike main memory.

There are several forms.  CDs, DVDs and Blu-ray discs are all examples of   opticalmagneticlineartertiary storage.  Traditionally, home computers have been fitted with   linearopticalstatelessmagnetic devices for long-term storage, although these are increasingly being supplemented with and replaced by solid state devices. 

These differ from their predecessors in that they   can store non-binary dataare rewritableare cheaper per unit of storagehave no moving parts.  Solid state drives or SSDs use   NANDORNOTAND flash memory to manage storage, entailing floating-gate   resistorstransistorscapacitorsLEDs, which can capture and store a charge.  

SSD storage is divided into   blockspagestrackssegments, which are themselves grouped into   segmentspagestracksblocks.  These must be reset to be completely blank whenever new data is to be written, although this process takes place extremely quickly.