Map generalisation is defined as a simplified representation of features on a map that is appropriate to its scale or purpose, without changing their visual form. Since maps are drawn at a reduced scale to serve a definite objective, they cannot show every detail of the actual ground.

Consequently, the cartographer must select only the information or data that is relevant to the selected theme and simplify it according to the map's needs. This process allows the map to effectively communicate general information like relief and drainage, or specific themes like population density, without becoming cluttered.