Layer

layer - [data structures] The visual representation of a geographic dataset in any digital map environment. Conceptually, a layer is a slice or stratum of the geographic reality in a particular area, and is more or less equivalent to a legend item on a paper map. On a road map, for example, roads, national parks, political boundaries, and rivers might be considered different layers.

[Category=Geospatial ]

Source: esri, 28 May 2012 08:22:05, http://support.esri.com/en/knowledgebase/GISDictionary/term/abbreviation