Grid
A grid is a two-dimensional data structure, representing a rectangular area. A grid contains cells, defined by a row and a column number.
For images/pictures (think e.g. of bitmaps or png files) usually only local row and column numbers are relevant.
In a GIS environment, a grid often represents a rectangle part of the world.
In the GeoDMS a grid is defined by a Grid Domain. Attributes with characteristics for the cells of the grid are called Grid data.