What is an economy? Is it things, stuff like cars, houses, washing machines and computers? Or is it services? The function of those things, payment services, cleaning services, heating, communication etc. We might say it is both. All the products around us deliver some functionality, but in order for them to do that they have to be made of some stuff. But somethings are made of more stuff than others. Take a mainframe computer of forty years ago and compare it to your phone which can deliver much more computational functionality with a lot less stuff to do it with.