The unavoidable answer
No flat map can preserve every property of Earth's curved surface everywhere. Peeling and flattening a globe requires stretching, compressing, cutting or overlapping parts of it. A map projection is the mathematical rule that controls those changes.
Accuracy needs a definition
A projection can preserve area, local angles, certain distances or selected directions, but not all of them globally at once. Calling a map accurate without naming the preserved property hides the most important design choice.
Mercator is locally conformal, so small shapes and angles behave usefully for navigation. Equal Earth is equal-area, so a region's share of the map matches its share of Earth's surface.
Scale also matters
A city map, continental map and world map solve different problems. A projection that performs well over a small region may be unsuitable for a global statistical map. Distortion should be evaluated over the area and task the reader actually needs.
How to choose
Start with the question. Use equal area when visual footprint carries quantitative meaning, conformal projections when local angle and shape are central, and suitable equidistant designs when particular distances matter. Sometimes an interactive globe is the clearest option.
Read the map's metadata
A trustworthy map should name its projection, source, date and territorial choices. Those details are not academic decoration: they tell you which comparisons the picture supports and which conclusions it cannot safely carry.
Explore the evidence
Sources and further reading
Continue with the Equal Earth projection guide, try the interactive map, or review our methodology.