PrintOverlay: a GIS operation by which two or more maps or layers registered to a common coordinate system are stacked upon each other and their corresponding data joined.
Digitizing: a GIS process of converting analog data, such as a paper map, to a digital format by tracing the analog data using a digital input device, such as a mouse.
Scanning: a GIS process whereby analog data, such as a paper map, is converted to a digital format by using a computer scanner.
Buffering: a GIS operation by which zones of specified radius or width are defined around selected vector features or raster grid cells.