Let's start with the simple options for text fields.
Simply turns all the characters of a string to lower-case.
You can set this at the field level or at the pattern level. 
Simply turns the first character to capital letter.
You can set this at the pattern level to only capitalize the first letter of the whole word. 
Simply uses the first letter of the string in both capital and small letter variations. 
Turns the first letter of every word (element or word in element) to capital letter resulting in CamelCaseVariation. 