This refers to the use of two controllers to drive a disk subsystem. Should one of the controllers fail, the other is still available for disk I/O. Software applications can take advantage of both controllers to simultaneously read and write to different drives.

See Disk duplexing.

The process of duplicating information from one set of drives to another so that an exact copy of the data always exists.  Similar to mirroring. See Also RAID.

Duplexing is the ability of a press or digital copier to print on both sides of a sheet without having to manually turn the sheet over.

A printer's ability to print on both sides of a page with one pass through the machine.

Duplexing hardware allows your printer, copier or scanner to capture images on both sides of a piece of paper. Often, this option is an accessory and only available on certain equipment models. Duplexing is another great way to reduce paper costs.

Term usually used in reference to melting metals or alloys in one type of furnace and transferring to another for holding, refining, etc. Common in the malleable field, where charges are melted in a cupola and transferred to air or electric furnaces for slight reduction of carbon and an increase in temperature.

A combination of both Lead/Lag and Alternating operations. The primary operation is alternating. However, when a secondary start level is reached, the non-active pump will start to assist in a lead-lag operation.

See Borrows.