Definitions of case sensitive on the Web:

• Text sometimes exhibits case sensitivity; that is, words can differ in meaning based on differing use of uppercase and lowercase letters. ...
  en.wikipedia.org/wiki/Case-sensitive

• Distinguishing upper- and lower-case letters. Often used in computer science to indicate a distinction is made in comparison or equality of letters based on case. For example, a case-sensitive password will not recognize "Password" and "password" as the same, but a case insensitive comparison would
  en.wiktionary.org/wiki/case_sensitive

• Distinguishing upper- and [[lowp
  en.wiktionary.org/wiki/case-sensitive

• Knows the difference between capital letters and lower case letters. A case-sensitive search for ""CASE" would not find "case".
  www.thecreativetrain.com/glossary.html

• When you are required to type in characters as either upper-case or lower-case in order for the string of characters to be accepted. ...
  www.usu.edu/sanderso/multinet/definiti.html

• sensible à la casse Lower and upper case letters are not treated as being the same; eg 'a' is not the same as 'A'. ...
  www.tbs-sct.gc.ca/cioscripts/gloss/gloss-alpha_e.asp

• Used to indicate that characters typed in will only be recognised if entered in the correct case.
  www.signature.gb.com/glossary.htm

• When an operation is case sensitive it makes a distinction between two names that don't have the same case. For instance, the names bill and Bill will be considered different in case sensitive system.
  www.davidgould.com/Glossary/Glossary.htm

• A program or function that differentiates between capital and non-capitalized letters or words. Something that is not case sensitive would view & ...
  www.pccomputernotes.com/pcterms/glossaryc.htm