Consider it this way; a circuit structure is any type of diagram which illustrates the way the circuit operates where the most important purpose is that the proper wiring of elements and their connection to each other rather than physical place relative to one another or planning prototypes. However, in some applications classifying diagrams can be challenging so accept this as overall information. I've discovered this is particularly true when dealing with much more complex circuits and electronics. I'm going to use a more straightforward but average industrial circuit since these circuit set ups are the exact same, but where you can see how each sort of diagram indicates the purpose of the circuit in their own ways.
Pictorial design diagrams, or graphic circuit diagrams are essentially the same thing with the identical function, but they use pictures of components within the circuit rather than symbols. Again, here is the identical specific circuit (almost except a controller was added and they are using conductors L1 and L3 instead of L1 and L2.
Right, Less clutter? I have enough information in each these diagrams to know exactly what this circuit does and also where to search for issues. Hope this helps. ( Note: do not confuse lecture or circuit diagrams with wiring diagrams; wiring diagrams will often demonstrate images of elements such as the pictorial, and also how the whole or portion of a circuit is wired. The distinction is that wiring diagrams typically put an emphasis on actual physical place of necessary elements relative to each individual that basically tell a layman Just What to do concerning the wiring. )
A schematic diagram refers to a specific kind of circuit structure that utilizes standard electrical/electronic symbols rather than images to show how a circuit (or portion of it) works. Below is a standard 3-wire motor controller circuit utilizing a typical short stop halt - start pushbutton channel utilizing a schematic diagram. (Momentary this means the button/switch you trigger will return to its default location once you physically let go of it, usually by a spring that forces the button/switch to do this.)
Here is another schematic diagram demonstrating exactly the same circuit, connections and components and it appears different but they fall into precisely the same category.
Here is a variant of a diagram. The principal aim of this diagram will be to show the logic (referring to electric control) of a circuit. This really is the one that I mostly come across in my line of work, and it is very successful for troubleshooting issues or learning the way the circuit functions. Some frequencies are so enormous that many kinds of schematic diagrams need to be read in increments from book form (generally with coded numbers so info can be easier found). Again, here is the exact same specific circuit since the first two weeks, but looking at it in ladder form.