Design is a process of conceptualizing, planning and executing the aesthetic, visual and interactive elements of a product or service. The design process involves different stages from problem analysis to creative conceptualization.
Prototyping is the process of creating a prototype or model of an object before it is manufactured. It enables designers to test their design decisions with users and other stakeholders on an early stage.
A prototype can be physical or digital, but it must be able to simulate some aspect of the final product so that people can interact with it. Prototyping also helps refine the design by identifying any problems with it before time and money are invested in making it.