The origin of the terms uppercase and lowercase might seem pretty self-explanatory. Upper and lower must be references to the height of the letters, and the use of case is presumably an offshoot of ...
More than one‐third of the world's population uses a writing system that includes both uppercase and lowercase letter forms. In these writing systems, capitalization is the use of an uppercase form ...
More than one-third of the world’s population uses a writing system that includes both uppercase and lowercase letter forms. In these writing systems, capitalization is the use of an uppercase form ...