Map cause cartographic generalization
Map projections: The foundation of the map is the plane on which it rests (whether paper or screen), but projections are required to flatten the surface of the earth. All projections distort this surface, but the cartographer can be strategic about how and where distortion occurs.
Generalization: All maps must be drawn at a smaller scale than reality, requiring that the information included on a map be a very small sample of the wealth of information about a place. Generalization is the process of adjusting the level of detail in geographic information to be appropriate for the scale and purpose of a map, through procedures such as selection, simplification, and classification.
Symbology: Any map visually represents the location and properties of geographic phenomena using map symbols, graphical depictions composed of several visual variables, such as size, shape, color, and pattern.
Composition: As all of the symbols are brought together, their interactions have major effects on map reading, such as grouping and Visual hierarchy.
Typography or Labeling: Text serves a number of purposes on the map, especially aiding the recognition of features, but labels must be designed and positioned well to be effective.
Layout: The map image must be placed on the page (whether paper, web, or other media), along with related elements, such as the title, legend, additional maps, text, images, and so on. Each of these elements have their own design considerations, as does their integration, which largely follows the principles of Graphic design.
Map type-specific design: Different kinds of maps, especially thematic maps, have their own design needs and best practices.