Using set and get in C Sharp

Question

What is the point of using set and get in C Sharp?

It seems variables are used differently in this language than in C++.

For some reason, you have to have a static variable defined like this:

public static uint Somenum
{
   set { m_somenum = value; }
   get { return m_somenum; }
}

and prior to this declaration, you need to have this:

public uint m_sumenum;

This seems to be the only way to expose a member of a class to other classes in C#.

The problem is that I seem to be doing this improperly because I get a compile error:

An object reference is required for the non-static field, metod, or property '.......m_somenum"

I think I see the problem.  The problem is that I cannot use a static varable like this.

So you have to instantiate the class in order to set these members of the class.

So how would you do the equivalent of a global class in C Sharp?

Would I do it something like this:

public clase SomeClass
{
    SomeClass someclass = new SomeClass();

 public static uint Somenum
 {
    set { m_somenum = value; }
    get { return m_somenum; }
 }
}

Or perhaps this "new" needs to be outside of the class in order to work.  So my next question is this.  How and where would that command be such that it the internal set methods could be accessed by the other classes in the code?