Block diagrams are used wherever functional processes, functional relationships and interdependencies of functional units are to be represented in a simplified manner. This applies equally to business management, organization and technology and, in the context of IT knowledge, to the functional relationships in modules, devices, systems, software and networks.
The individual functional units of a block diagram are represented as blocks and their interaction is indicated by lines and arrows. Corresponding diagrams can be broken down to individual components or electronic circuits. Depending on the complexity and size of the module, device or system, the blocks are assigned a lower or higher functionality, which is often underlined by pictograms.
A block diagram represents a simplification of the functional relationships without going into detail about how the functional blocks work. It is different with circuit diagrams and construction plans, which go into the necessary details. For example, a measuring transducer in a block diagram may consist of the functional units overvoltage protection, sample and hold, A/D converter, shift register and display. Or an RF receiver may consist of the functional blocks preamplifier, mixer, oscillator, and IF amplifier. In such a diagram the interfaces to the further function blocks, signal functions or level values can be entered.