Demand-driven innovation is about understanding the users' real needs. Developing solutions that work for your users can be ensured by involving users in the innovation process.
Interaction Design is about understanding the interaction between people and products or services. This understanding comes in handy when making inclusive digital solutions. To gain insight into how people and solutions interact need to be tested, and you have to talk to the users of the solutions throughout the development process.
Designing a service is a complex process that uses the knowledge from multiple disciplines. It becomes increasingly important to make good, efficient services that have a holistic focus and create great experiences for users. In service design, there are many good methodologies that can provide insight into how existing services can be improved and how to create new services in a structured and comprehensive manner.