C# .Equals(), .ReferenceEquals() and == operator

My understanding of these three was:

• .Equals() tests for data equality (for the lack of a better description). .Equals() can return True for different instances of the same object, and this is the most commonly overridden method.

• .ReferenceEquals() tests whether or not two objects are the same instance and cannot be overridden.

• == is the same as the ReferenceEquals() by default, but this CAN be overridden.

But C# station states:

In the object class, the Equals and ReferenceEquals methods are semantically equivalent, except that the ReferenceEquals works only on object instances. The ReferenceEquals method is static.

Now I don't get it. Can anyone shed some light on this?