Editing Reading (computer) (section)

=== Flash ===
{{main article|Flash memory}}
Flash memory stores information in an array of memory cells made from [[floating-gate transistor]]s. Flash memory utilizes either NOR logic or NAND logic.

In [[NOR gate]] flash, each cell resembles a standard [[MOSFET]], except the transistor has two gates instead of one. On top is the control gate (CG), as in other MOS transistors, but below this, there is a floating gate (FG) insulated all around by an [[oxide]] layer. The FG is interposed between the CG and the MOSFET channel, and because the FG is electrically isolated by its insulating layer, any [[electron]]s placed on it are trapped there and, under normal conditions, will not discharge for many years. When current flow through the MOSFET channel [[binary code]] is generated, reproducing the stored [[data]].

[[Sheffer stroke#NAND gate|NAND gate]] flash utilizes [[tunnel injection]] for writing and [[tunnel release]] for erasing. NAND flash memory forms the core of the removable [[USB]] storage devices known as [[USB flash drive]]s, as well as most [[memory card]] formats available today.