You’ll encounter three types of diagrams in electricity and electronics: block, schematic, and pictorial. Each type of diagram serves its own special purpose.
1. A block diagram gives you an overview of how the discrete circuits within a device or system interact. Each circuit is represented with a “block” (a rectangle or other shape, depending on the application). Interconnecting lines, sometimes with arrows on one or both ends, reveal the relationships between the circuits.
2. A schematic diagram (often simply called a schematic) includes every component that a circuit contains, with each component having its own special symbol. This book is devoted mostly to schematics.
3. A pictorial diagram, sometimes called a layout ...