What factors explain the nature of software?

Are there deeper, more fundamental aspects of software that can help us think beyond surface-level matters? I’ve come to think that a triad of interacting factors best explains what software is and, by extension, why software is difficult:

• Software occupies a liminal state between the constraints of the physical world and an anything-goes fantasy world. We frequently mistake the constraints that software faces.

• Our ability to specify what a given piece of software should be is limited by the circular specification problem. We nearly always have to fully build the software in order to know precisely what we want it to be.

• Software is subject to the observer effect. The act of seeing the software in action changes what we – or more often others – think the software should be, sometimes radically.

• Larry Tratt

(The whole thing's worth reading)