Did you see that? Right there…back at the beginning of that first sentence. What are we talking about? The word “Did," of course! Did you notice anything strange about that word? Did you? For example, did you notice that it contained one letter twice but it looked different each time it appeared?
“Did," when it appears at the beginning of a sentence, starts out with an uppercase “D" and ends with a lowercase “d." They're the same letter, but they look different. Have you ever given any thought to how strange that is? Why can't all letters simply be the same? Why do we have both uppercase and lowercase letters?
When it comes to letters, case refers to whether letters are written in larger uppercase form, which is also often known as majuscule or capital letters, or smaller lowercase form, which is also known as miniscule or small letters. For example, the first three letters of the alphabet in uppercase form are A, B, and C. Those same three letters in lowercase form are a, b, and c.
Over time, however, it was only natural that smaller versions of each letter would develop. This probably happened as letters were written quickly. To save time and space, letters became smaller and more rounded as scribes hurried to finish their work.
These smaller versions of letters eventually evolved into an entire miniscule set of letters. Compared to majuscule versions, the miniscule versions offered improved and faster readability in addition to being easier and faster to write.
At first, scribes would only use majuscule or miniscule letters, but not a mixture of both. That changed over time, though. Although there were no official capitalization rules in the English language until the early 18th century, scribes had traditionally written certain letters, such as nouns and the first letters of sentences, in a larger, distinct script for hundreds of years.
Today, lowercase letters are used most frequently, with uppercase letters reserved for special purposes, such as capitalizing proper nouns or the first letter of a sentence. The terms “uppercase" and “lowercase" come from the way in which print shops were organized hundreds of years ago.
Individual pieces of type were kept in boxes called cases. The smaller letters, which were used most often, were kept in a lower case that was easier to reach. Capital letters, which were used less frequently, were kept in an upper case. Because of this old storage convention, we still refer to small letters as lowercase and capital letters as uppercase.
The distinction between uppercase and lowercase letters doesn't exist in all languages, though. Certain Eastern and Asian writing systems, including certain Indian, Chinese, and Japanese alphabets, do not distinguish between uppercase and lowercase letters.