Case sensitivity

In computers, case sensitivity defines whether uppercase and lowercase letters are treated as distinct (case-sensitive) or equivalent (case-insensitive).

Case sensitivity may differ depending on the situation: Some programming languages are case-sensitive for their identifiers (C, C++, Java, C#, Verilog,[2] Ruby,[3] Python and Swift).

Others are case-insensitive (i.e., not case-sensitive), such as ABAP, Ada, most BASICs (an exception being BBC BASIC), Common Lisp, Fortran, SQL (for the syntax, and for some vendor implementations, e.g. Microsoft SQL Server, the data itself)[NB 2] Pascal, Rexx and ooRexx.

In addition, some Mac Installers assume case insensitivity and fail on case-sensitive file systems.

Later, with VFAT in Windows 95 the FAT file systems became case-preserving as an extension of supporting long filenames.