Solution design consists of designing the blocks. Initial high level design will need to be governed to confirm that it adheres and can be mapped to the overall Solution Design. High Level design will then need to be elaborated into detail design.

HLD -- High Level Design (HLD) is the overall system design - covering the system architecture and database design. It describes the relation between various modules and functions of the system. data flow, flow charts and data structures are covered under HLD.