As a designer, I have worked on various product design projects that cover different domains, platforms and audiences. Product design is a wide and diverse field that involves both digital and physical products and services with different hierarchies of interaction, contexts of use, and limitations and challenges.
It is a rich and rewarding field that always has an interesting challenge to solve.
Physical and Digital products often require similar skills but demand very specific knowledge and experience.
Physical
Products that people interact with physically in the real world like cars, home appliances, furniture, etc. Requires manufacturing to be produced and logistics to be transported.
The UX of a physical product relies a lot on ergonomics, physics, CMF (colour, material, and finishing), which are directly impacted by cost. Having a good knowledge and understanding of human anatomy, human senses, mechanical force, manufacturing technology and process, types of materials, and different way to apply colour are some examples that can influence a product experience.
The user interface can be mechanical (e.g. valves and handles), analogue (e.g. switches and dials) or electronic (e.g. capacitive and microcontroller) and is usually made of several stationary components.
Fun fact: you work a lot more with millimeters than pixels.
Digital
Products that people interact with virtually usually through a screen or display, like mobile applications, computer applications, TVs content, etc. Requires software development and are usually transferred digitally through a network or portable data storage.
The UX of a digital product relies a lot on accessibility, navigation, and information, which are directly impacted by the performance of the hardware and infrastructure behind it. Having a good understanding of human perception, cognitive behaviour, system, software, and graphics are some of the examples that can influence a product experience.
The user interface is mainly software development mostly influencing the front-end and GUI.
Fun fact: the colour you defined has a high chance to be seen as a different hex value.
Hybrid
The combination of physical and digital at different levels. It depends on the relationship between the physical and digital parts, the hierarchy, the type of business, and the user, where usually the digital is dedicated to controlling the physical product or system either embedded, like the Tesla touch screen that controls the air conditioner, or separated like a mobile application that can control your Philips Hue lights or as a dashboard app that aggregates all your devices like HomeKit or Google Home.