What is an app? I honestly have no idea

I’m trying to get my dad to use his iPhone. Being hard of hearing – and I’m going the same way on that front – it would be so much easier to communicate if he could text better. A problem he and my mum have is that their screens don’t seem to respond to their fingers properly. I’ve blamed the way they stab so desperately at their phones, but I read somewhere that it’s because older people have drier skin on their hands, which makes them less touchscreen-capable.

Either way, my dad’s particular issue is kind of conceptual. Time and again, he asks me the same question: “What is an app?” I tell him: “Well, it’s just an, erm, app.” This isn’t much help, but I eventually find some form of words that has him nodding and we move on. Then, a month or so later, the same question again, delivered with ever more brow-furrowing angst: “Ade, please can you explain, what is an app?” Whatever I say doesn’t seem to help the poor chap.

Google certainly doesn’t help with this, serving up a definition that, for my dad, prompts as many questions as it answers: “Simply put, an app is a type of software that allows you to perform specific tasks. Applications for desktop or laptop computers are sometimes called desktop applications, while those for mobile devices are called mobile apps. When you open an application, it runs inside the operating system until you close it.” I haven’t even shared this “explanation” with him yet. There’s no point.

I’ve tried everything. I have sought to work up a decent analogy, but without success. Getting him to think of his record player as a kind of app to play his records didn’t work. And neither did one about his car and its engine, which ended up confusing me more than him. Suggestions welcome.