A hierarchical diagram illustrating layers from application software to physics in computing systems. Alt text provided by Elsevier.The diagram illustrates a hierarchy of computing systems, starting from the top with 'Application Software' which includes a text box with 'greater than"hello world!"'. Below it is 'Operating Systems' represented by a laptop icon. 'Architecture' follows, depicted with a series of horizontal bars. 'Micro architecture' is next, shown with two blocks connected by arrows. 'Logic' is represented by a rectangle with a plus sign inside. 'Digital Circuits' is illustrated with a logic gate symbol. 'Analog Circuits' is depicted with an operational amplifier symbol. 'Devices' is shown with a transistor symbol. Finally, 'Physics' is represented by an atomic structure icon. Alt text provided by Elsevier.Peripherals