User Flows, Wireframes, Mockups
User flows are visual diagrams capturing step-by-step how the users navigate and use your product in order to reach their goals.
Wireframes are quick sketches that capture what the user needs to see and do on every step within a given flow.
Mockups are conceptual designs to help us communicate aesthetic values as well as more visual detail.
There are more types of design deliverables (production designs, interactive prototypes), and they are all targeted towards communicating different types of information for different purposes.
Request more information about the type of designs you need in your project at the moment.