A design diagram refers to a particular kind of circuit structure which uses standard electrical/electronic symbols instead of images to show how a circuit (or part of it) functions. Below is a normal 3-wire motor controller circuit utilizing a standard momentary stop - start pushbutton station working with a schematic diagram. (Momentary this means the button/switch you trigger will return to its default location once you let go of it, typically by a spring that forces the button/switch to get this done.)
Pictorial design diagrams, or pictorial circuit diagrams are basically the same thing with exactly the identical function, but they use images of components inside the circuit instead of symbols. Again, here's the identical specific circuit (almost except a control transformer was added and they are using conductors L1 and L3 rather than L1 and L2.
Following is a variant of a diagram. The principal aim of this diagram will be to show the logic (speaking to electrical management ) of a circuit board. This diagram is the one that I mostly come across in my own line of work, and it is very successful for troubleshooting problems or learning how a circuit works. Some frequencies are so huge that many kinds of schematic diagrams have to be read in increments in book form (normally with coded numbers so that information can be easier found). Again, here is the exact same exact circuit as the first two, however looking at it in ladder form.
Here is another schematic diagram demonstrating precisely the same circuit, connections and components and it seems different but they both fall into precisely the same category.
Much less clutter? I've got enough info in each one these diagrams to know precisely what this circuit does and where to search for problems. Hope this helps. ( Note: do not confuse circuit or schematic diagrams with wiring diagrams; wiring diagrams will usually demonstrate images of components such as the pictorial, and also the way the whole or part of a circuit has been wired. The difference is that wiring diagrams usually place an emphasis on actual physical location of necessary components relative to each individual that essentially tell a layman exactly what to do concerning the wiring. )
Consider it this way; a circuit structure is any type of diagram which demonstrates how a circuit operates where the principal goal is the appropriate wiring of components and their connection to each other instead of physical location relative to one another or intending prototypes. Nonetheless, in some applications classifying diagrams can be hard so choose this as overall information. I've discovered this is particularly true when working with much more complicated circuits and electronic equipment. I'm likely to work with a more straightforward but average industrial circuit since these circuit setups are exactly the same, but yet where you can see how each kind of diagram shows the use of the circuit in their own ways.