In process control, block diagrams are a visual vocabulary for describing activities in a complex system in which cubes are black boxes which represent mathematical or logical operations that happen in order from left to right and top to base, although not the physical entities, like processors or relays, that execute those operations. It is likely to create such block diagrams and execute their functionality with technical programmable logic control (PLC) programming languages.
A block diagram is a type of a method in which the main parts or functions are represented by cubes linked by lines that reveal the connections of the blocks.
To create an analogy to the map making planet, a block structure is similar to a highway map of an entire nation. The significant cities (serves ) are listed but the small county roads and city roads aren't. When troubleshooting, this large degree map is helpful in narrowing down and isolating in which a problem or error is.
For example, a block diagram of a radio is not predicted to show each and every connection and dial up and switch, but the design diagram is. The schematic diagram of a radio does not demonstrate the width of every connection from the circuit board, however the layout diagram does.
In biology there is a growing use of engineering principles, techniques of analysis and methods of diagramming. There's some correlation between the block structure and what's called Systems Biology Graphical Notation. As it is there is use created in systems economics of this cube diagram technique exploited by controller engineering in which the latter itself is a program of management theory.
Block diagrams rely upon the principle of the black box where the contents are hidden from view either to avoid being distracted by the details or because the details aren't known. We all understand what goes in, we know what happens, but we can't see how the box does its own work.
In electrical engineering, a design may often begin as a quite large level block diagram, becoming more and more detailed block diagrams because the design progresses, eventually finishing in block diagrams comprehensive enough that each individual block is easily executed (at which point the block structure can be also a schematic diagram). This is referred to as top down layout.  Geometric shapes are often utilized in the diagram to help interpretation and describe meaning of the procedure or version. Each engineering field has their own meaning for every form. Block diagrams are used in every discipline of technology. They're also a valuable source of concept building and educationally beneficial in non-engineering areas.
A good example of this is that the function block diagram, among five programming languages found in section 3 of the IEC 61131 (see IEC 61131-3) standard that is quite formalized (see formal system), with strict rules to how diagrams should be built. Directed lines have been utilised to connect input variables to block input signal, and prevent presses to output factors and inputs from different cubes.
Block diagrams are typically used for higher level, less detailed descriptions that are meant to describe overall concepts without concern for the particulars of execution. Compare this with the schematic diagrams and layout diagrams used in electrical engineering, which show the implementation information of electrical parts and physical structure.