Difference between VARCHAR and VARCHAR2?
In case of varchar, if you enter value less than 10 characters then remaining space can not be deleted. It used all 10 characters where as in varchar2 extra space is automatically deleted.
Why is a programming language such as JAVA is platform independent where as programming language such as .NET is not?
Java compile code to byte code which is intermediate between source code and machine code. This byte code can be run on any platform thus making it as WORA-Write Once Run Anywhere where as the same is not the case with .NET
Does all HTML tags need closing tag?
No, few tags like line break does not need an End tag.