In summary
A service designer is working on all types of interactions that don't have to be tangible.
A Product designer either works on the very physical stuff or the very digital stuff.
A product manager is basically a team leader.
My two cents
As always, these jobs have differences and have things in common too.
The secret is that they often have much more in common than what we believe. But, that's a secret.
Service Designer
So a service designer is working on creating and improving experiences between people and organizations.
These experiences don't have to be physical. This means it can be a phone call. It can be the interaction that you have with someone at the reception. It can be your interaction you have with the opening hours on the door of a shop.
These are all the tiny pieces of interactions that a service designer tries to bring together to create a coherent experience for the people that use a service.
But the service designer also works on the backstage stuff.
This means a service designer also tries to make it possible to create services in a way that doesn't make employees want to kill themselves. And therefore a service designer also thinks about processes, and elements of the workplace.
Product Designer
A product designer is someone who is creating something tangible.
And here, the definition depends on how old you are.
Back in the days, our product designer was really someone building furniture, designing objects like mug, or anything else that you could put it in your hands.
But today, the definition of product designer has changed a bit.
In fact often today, a product designer is someone who is working on a digital product.
It can be a website. It can be an app. It can be a tool used by employees.
So when we speak about product designer: Which type of product designer are we speaking of?
And obviously product designers also have to think about things like processes. For example, designing the most beautiful chair is a good thing. But a good product designer, also thinks about how this chair will be produced. And therefore he is also involved with the manufacturing side of things.
But the product designer, won't be the one deciding what happens with the support of the product that he designs. That's where the service designer will usually also come in play.
Product Manager
A product manager is basically the person who works with a team of designers, developers, and other people to create a product.
Because yes to create the product a designer isn't enough. You need a lot of other specialties.