This documentation is for users.
The relationship between maps is best described with an example. Imagine a map of a continent, defined to have a scale of 1 tile = 25km. At some point later, it becomes desirable to detail one region of the map at a higher resolution, maybe 1 tile = 5km.
When this is done, the region is selected and cropped (maybe a 30x30 tile part of the original map). After cropping, the new map is rescaled to the higher resolution, giving a 150x150 tile map, with each tile representing 5km.
The original map is the parent, the new map the child. The child map keeps a record of their parent, and also the location in the parent from which they were cut.
If a third map is generated from the parent, then both children are siblings of each other, and may overlap. Facilities exist to merge siblings so that overlapping areas are forced to be identical. Changes to the children can also be ported back into the parent (though at the lower resolution).
The hierarchy of maps becomes important when such merging is done, but it is all kept track of transparently by the application.
Template: A template holds descriptions of tiles and objects for use in a map. Each template has associated images to go with it, and defines whether the map has hexagonal or square tiles.
Terrain: Terrain is the lowest level layer drawn on the map. It is what people walk on, rather than bump into. In world maps it describes the general vegetation and climate.
Features: Features modify the terrain, or sit upon it. Hills and mountains are features in world maps. Walls and doors are features in local maps. Features are always drawn ontop of a terrain tile, and each tile has at most a single feature.
Things: Things are free floating objects which are not based on the tile grid. Multiple things can sit on the same tile, or across two or more tiles. Things can be of any shape or size. On world maps, things represent towns and cities. On local maps, they may be tables, beds or chests.
Path: A path is a free floating line on the map. Like things, they are not restricted to tiles. They generally represent roads or rivers.