Instance and Static Method with this Keyword

In brief: instance method gets implicit parameter "this" used to access the instance on which the call is done. Static method does not have it; it is roughly equivalent to the pre-OOP function/procedure; in .NET, a static method cannot be virtual (but there are technologies where it can be).

To illustrate instance method mechanism, consider this:

class MyClass {
   internal void SomeInstanceMethod() { // "this" parameter is not shown, but it's there
       this.SomeMember = 3; // which SomeMember object is this? see below...
   }
   internal int SomeMember { get; set; }
}

MyClass myInstance = new MyClass();

myInstance.SomeInstanceMethod();
// when you enter SomeInstanceMethod stack frame in this call,
// this equals to myInstance
// if it was a static method, the call would be equivalent to
// SomeInstanceMethod(myInstance)

As you can see, myInstance.*() call is the way to pass instance parameter "this" to the method.

—SA