Contrary to schematics, blueprints and layout diagrams, block diagrams don't portray the essential detail for physical structure. Block diagrams are made easy so as to not cloud concepts.
Block diagrams are utilized heavily in design and engineering of diagrams such as electronic equipment, hardware, software and procedures. Most commonly, they signify concepts and systems at a higher level, less detailed overview. The diagrams are helpful for troubleshooting technical difficulties.
The simplification in block diagrams may also be helpful when demonstrating a notion, but concealing the internal workings of potentially secret intellectual property (IP). Top-down design in electrical technology often progresses through increasingly detailed block diagrams. Block diagrams in process control reveal the functions of operations but not the elements that execute them. The purposes of block diagrams may then be executed with programmable logic controls (PLC).
An entity relationship diagram (ERD), one case of a block diagram, represents an advice system by demonstrating the relationships between people, objects, places, concepts or events within that system. (See a picture in the ERD definition webpage.)
Block diagrams can also be utilized in a context. In the study of biology, as an instance, block diagrams are used to show biological functions and interrelations.