What is Change Text Case?

Here is an explanation of all the different modes the tool supports:
Sentence Case:
Makes everything lowercase except the first character and "I".
Title Case:
Capitalize the first character of each word except common stop words like 'and', 'at' etc
Capital Case:
Capitalize the first character of each word.
Lower Case:
Lower Case everything inside the string.
Upper Case:
Upper Case everything inside the string.