What is case sensitive?

Case sensitive refers to a type of sensitivity in which the distinction between uppercase and lowercase letters is important. In computer programming and computing in general, case sensitivity is a significant factor. It is used in programming languages, passwords, usernames, file names, and directory names. For examples, PASSWORD and password are two distinct and different strings in a case-sensitive environment.

In a case-insensitive environment or system, PASSWORD and password would be considered the same. In simpler terms, if the system is case sensitive, 'abcd' and 'ABCD' are different, but if it is case insensitive, they are the same.

Different programming languages and systems may have different rules around case sensitivity. For example, in CSS, class names are case-insensitive, whereas in HTML, IDs are case-sensitive. It is essential to understand the rules of case sensitivity for the system or programming language being used to avoid errors and misconceptions.