Different Casing styles or Naming conventions in programming. What is Camel casing Pascal casing Upper casing Lower casing and Difference between them

There are mainly four different casing styles that is followed while programming, they are
1) Camel casing (also called as lower camel casing)
2) Pascal casing (also called as upper camel casing)
3) Upper casing
4) Lower casing

Camel casing Capitalizes the first character of each word except the first word
In camel casing the first letter of the first word is in lower casing.

If any words are concatenated then the first letter of the concatenated word is in uppercase followed by lower case characters.

Example: calculateInterest, operationResults, propertyDescriptor, htmlTag 
Usage:
i) Variable names
ii) Object reference variables
iii) method arguments

Pascal casingCapitalizes the first character of each word (including acronyms over two letters in length)
In Pascal casing the first letter of the word is in uppercase following characters are in lowercase.
If any words are concatenated then the first letter of the word is also in uppercase followed by lower case characters.

Example: DataAccessClass, PropertyDescriptor, HtmlTag, IOStream 
Usage:Class names 

Upper casing - In upper casing all the characters are in upper case.

Example: METHOD_POST
Usage: Constants

Lower casing - In lower casing all the characters are in lower case.

Example: objectvariable
Usage: Variables


Links: