visual rectangle editor. work on some background image. rectangles are saved as an object in json format (so in the editor you can specify names for the rectangle objects, thats the object/“map”).
useful for tiles: a grid is a set of a certain amount and size of rectangles that assigns them the numbers [0][0] to [w][h], and groups them to a json object named after some user input.
then you import the json in a tile loader library which then loads either the tile located at a logical coordinate (place in rectangle grid, not pixel grid) or some tile named after something.
then the game can just make some cool things with it.