Of this abstraction. The values for getRadius() or getCircumference() in the above example may very well be saved instantly, or they might be calculated, it won't make any difference into the caller; the setters may or might not have Unwanted effects; it won't make any difference into the caller. [1] https://propertyingurugram.in/m3m-expects-rs-5000-cr-in-sales-through-13-acre-land-acquired-in-noida/