Case-sensitive

Text sometimes exhibits case sensitivity; that is, words can differ in meaning, or can be distinguished in a computer search, based on differing use of capital and lowercase letters. Words usually mean the same when written with capital and with lowercase letters, but not always; for example:

The opposite term of "case-sensitive" is "case-insensitive".

In computers, the following are sometimes case-sensitive, sometimes not:

Some computer languages are case-sensitive for their identifiers (C, C++, Java, C#, Verilog,Ruby and XML). Others are case-insensitive (i.e., not case-sensitive), such as Ada, most BASICs (an exception being BBC BASIC), Fortran, SQL and Pascal. There are also languages, such as Haskell, Prolog and Go, in which the capitalization of an identifier encodes information about its semantics.

A text search operation could be case-sensitive or case-insensitive, depending on the system, application, or context. The user can in many cases specify whether a search is sensitive to case, e.g. in most text editors, word processors, and Web browsers. A case-insensitive search is more comprehensive, finding "Language" (at the beginning of a sentence), "language", and "LANGUAGE" (in a title in capitals); a case-sensitive search will find the computer language "BASIC" but exclude most of the many unwanted instances of the word. For example, the Google search engine is basically case-insensitive, with no option for case-sensitive search. In Oracle SQL most operations and searches are case-sensitive by default, while in most other DBMS's SQL searches are case-insensitive by default.

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