Overlay

Overlay may refer to:

Computers

 * Overlay network, a computer network which is built on top of another network
 * Video overlay, techniques to display video on computer display
 * Hardware overlay, one type of video overlay that uses memory dedicated to the application
 * Another term for exec, replacing one process by another
 * Overlay (programming), a technique to reduce the amount of memory used by a program
 * Overlay keyboard, a specialized keyboard with no pre-set keys
 * Keyboard overlay, a sheet of printed text sitting between the keys, depicting an alternate keyboard layout
 * Vector overlay, an analysis procedure in a geographic information system for integrating multiple data sets

Other uses

 * Overlay architecture, temporary elements that supplement existing buildings and infrastructure for major sporting events or festivals
 * Overlay control, in semiconductor manufacturing, for monitoring layer-to-layer alignment on multi-layer device structures
 * Overlay plan, a method of introducing new area codes in telephony
 * Historic overlay district, a zoning district that applies special rules to a portion of other districts, usually for historic or conservation reasons
 * When the payoffs in gambling are greater than the costs; see Advantage gambling