Can we call Static method by an object ?

Things like the method calling conventions, the way that parameters are pushed on the stack and things like that are useful to understand but it might be too complicated for a beginner.

The important thing is that there is only one of a static thing. I would say one instance but everyone insists that it is not an instance, and I think it is confusing for beginners to say that it is not an instance. There is only one object of a static class; always one and only one. So you refer to that one object using the class name.

C# does not allow you to invoke static member using typical instance-members format: a.method(). This becomes clear if you understand method calling conventions. When instance-level method is invoked, first argument pushed to the stack is this pointer. When static method is invoked, this pointer does not exist and it is not pushed to the stack. Situation with properties is exactly the same, because its accessors are compiled into property_get and property_set methods, thus it becomes the same as in case of methods.

C# only allows you to invoke static members from inside the type which defines them (or inherits them) without stating the type name. So if you have class MyClass with static method DoSomething(), then from any other class you must write MyClass.DoSomething() (and you can't invoke it using the instance a as a.DoSomething()). Only from inside MyClass and classes derived from it (including from instance-level methods and properties) you can simply write DoSomething() as if it was an instance-level method. Under the hood, this compiles the same as if called with type name: MyClass.DoSomething().

Zoran