Hierarchical schematic diagrams (designs)
A hierarchical design is a large circuit diagram in which various schematic diagrams are placed onto multiple design sheets at different levels of importance and are interconnected vertically.
Onto the higher level are placed hierarchical blocks, having hierarchical pins and onto the lower level are placed hierarchical ports. The electrical connection is done vertically, in an invisible manner, the same used in the case of net aliases (in that case the invisible electrical connection is done horizontally).
A hierarchical schematic diagram (design)