To make an analogy to the map creating world, a block diagram is very similar to a highway map of an whole nation. The significant cities (serves ) are recorded but the small county roads and city streets are not. After troubleshooting, this elevated degree map is useful in narrowing down and isolating where a problem or error is.
In process management, block diagrams are a visual language for describing activities within a intricate system in which blocks are black boxes that represent logical or mathematical operations which happen in order from left to right and top to bottom, although not the physical entities, like chips or relays, that execute these operations. It is likely to create such block diagrams and execute their performance with technical programmable logic control (PLC) programming languages. )
In biology there's a growing use of engineering fundamentals, techniques of research and methods of diagramming. There is some correlation between the block structure and what's called Systems Biology Graphical Notation. Since it is there's use made in systems biology of the block structure technique exploited by controller engineering where the latter itself is a program of control theory.
Block diagrams are generally used for higher level, less detailed descriptions that are meant to clarify overall concepts without concern for the details of execution. Contrast this with the design diagrams and layout diagrams used in electric technology, which reveal the implementation information of electrical parts and physical construction.
A block diagram is a type of a system where the main components or functions are represented by cubes linked by lines which show the relationships of the cubes. They are greatly utilised in engineering in hardware design, digital design, software design, and process flow diagrams.
Block diagrams rely on the principle of the black box in which the contents are concealed from view to avoid being distracted by the details or because the details are not known. We know what goes in, we all know what goes out, but we can't see the way the box does its work.
A good example of that is the function block structure, one of five programming languages found in part 3 of the IEC 61131 (see IEC 61131-3) benchmark that is highly formalized (see proper method ), with strict rules to how diagrams should be built. Directed lines are utilised to connect input factors to block input signal, and block outputs to output factors and inputs from other blocks.
In electrical engineering, a layout will often start as a rather high level block diagram, getting more and more detailed block diagrams as the design develops, finally finishing in block diagrams comprehensive enough that each individual block can be readily executed (at that point the block structure will be also a schematic diagram). This is known as top down design.  Geometric shapes are often utilised at the diagram to assist interpretation and describe meaning of this process or model. Each engineering field has their own meaning for each shape. Block diagrams are employed in each discipline of technology. They are also a valuable source of theory building and educationally beneficial in non-engineering disciplines.
As an example, a block diagram of a radio is not predicted to demonstrate each and every link and dial and switch, but the design diagram is. The schematic diagram of a wireless does not show the width of each connection in the circuit board, but the layout diagram will not.