A design sprint workshop is a 1-2 day workshop for the product teams (designers, developers and clients) to align on the problems to solve, generate as many design concepts as possible and finally decide on the best design solutions as a team.
This helps stakeholders, designers and developers explore ways to best optimise the user experience. The team gains insights from each other based on unique perspectives (of being a client, designer, developer) and comes to a consensus on the best possible solution(s).
Wireframes are first-draft designs of apps to show layout ideas and user flow in lines— usually without much emphasis on visuals and interactivity.
Wireframes can be done quickly and are usually enough to present or test how efficient a flow is.
User flow mockups are high-fidelity designs of the app flows. They present the actual look and style of the app. Colours, fonts, icons and images would be rendered here.
Mockups are the second best testable representation of an app as they render almost everything about the user experience except interactivity. Mockups are the primary deliverables of UX designs.
Clickable prototypes are - as their name implies - a "clickable" version of user flow mockups where users can interact with the app design either on screen or via mobile.
Clickable prototypes are the best representation of an app for usability testing & delivering designs to developers, as they encompass all aspects of the user experience, including interactivity.