A design diagram refers to a particular type of circuit structure that uses standard electrical/electronic symbols rather than images to show the way the circuit (or part of it) works. Below is a standard 3-wire motor controller circuit employing a typical short stop halt - start pushbutton station utilizing a schematic diagram. (Momentary this means that the button/switch you trigger will go back to its default location once you physically let go of this, usually by a spring which forces the button/switch to get this done.)
Here's another schematic diagram showing exactly the identical circuit, connections and components and it appears different but they fall into precisely the same category.
Here's a version of a schematic diagram. The most important point of this diagram will be to demonstrate the logic (referring to electrical management ) of a circuit. This diagram is the one that I mostly encounter in my own line of work, and it's extremely effective for troubleshooting issues or learning the way the circuit works. Some circuits are so huge that many types of schematic diagrams need to be read in increments in novel form (generally with coded numbers so information can be easier found). Again, here's the exact specific circuit because the first 2, however, considering it in ladder shape.
Much less mess, right? I have enough information in each one these diagrams to know exactly what this circuit does and also where to start looking for problems. Hope that this helps. ( Note: don't confuse lecture or circuit diagrams with wiring diagrams; wiring diagrams will typically show pictures of elements like the pictorial, and also the way the entire or portion of a circuit will be wired. The difference is that wiring diagrams typically put an emphasis on actual physical place of necessary elements relative to each other that basically tell a layman exactly what to do about the wiring. )
Think of it this way; a circuit diagram is any type of diagram which illustrates how a circuit functions where the principal goal is that the appropriate wiring of elements and their connection to each other instead of physical place relative to each other or intending prototypes. However, in some applications classifying diagrams can be difficult so choose this as overall advice. I have found this is especially true when dealing with much more complicated circuits and electronics. I'm likely to use a simpler but typical industrial circuit since these circuit setups are exactly the same, but nevertheless where you can observe how each type of diagram shows the use of the circuit in their own manners.
Pictorial schematic diagrams, or pictorial circuit diagrams are essentially the exact same thing with exactly the same purpose, however they use images of components within the circuit rather than symbols. Again, here's the exact exact circuit (almost except a controller was included and they are using conductors L1 and L3 instead of L1 and L2.