What is underscore before a variable mean?

Questions & Answers
1

For example

var _myVariable;

VS

var myVariable;

2

I have seen some people use this convention to indicate a 'Constant', a variable that should never change.

But,technically, it doesn't mean anything.

3

Variable names are just identifier for the variable. The name itself has no meaning to the program or the compiler. There are a lot conventions on how you should / can name your variables. I don’t use the hungarian notation myself most likly because C# provide the type information through intelliSense ;). All i usually use is my habit (from C++) to prefix private or protected member variables with “m_”. A lot people use just “_” but some other use it for different meanings.