A schematic diagram refers to a specific sort of circuit diagram which utilizes standard electrical/electronic symbols rather than images to show how a circuit (or portion of it) works. Below is a typical 3-wire motor control circuit utilizing a typical momentary stop - start pushbutton station utilizing a schematic diagram. (Momentary this means the button/switch you trigger will go back to its default location once you physically let go of it, typically by a spring that forces the button/switch to get this done.)
Pictorial schematic diagrams, or pictorial circuit diagrams are basically the same thing with exactly the exact identical function, however they use pictures of elements within the circuit rather than symbols. Again, here's the same exact circuit (virtually except a controller was added and they are utilizing conductors L1 and L3 rather than L1 and L2.
Here is another schematic diagram demonstrating exactly the identical circuit, components and connections and it appears different but they fall into exactly the exact identical category.
Here is a specialized version of a diagram known as a ladder structure. The major intent of this diagram will be to demonstrate the logic (referring to electric management ) of a circuit. This really is the one that I mostly come across in my own line of work, and it's very effective for troubleshooting problems or learning how a circuit functions. Some circuits are so enormous that many kinds of schematic diagrams have to be read in increments in novel form (usually with coded numbers so info can be simpler found). Again, here's the exact specific circuit since the first 2, but considering it in ladder type.
Consider it this way; a circuit structure is any type of diagram that illustrates the way the circuit functions where the main objective is the proper wiring of components and their connection to each other rather than physical place relative to each other or intending prototypes. However, in some uses classifying diagrams can be difficult so choose this as general information. I've found this is especially true when working with more complex circuits and electronics. I'm going to work with a more straightforward but typical industrial circuit since these circuit set ups are exactly the same, but where you can observe how each sort of diagram shows the purpose of the circuit in their own ways.
Less mess? I've got enough information in each of these diagrams to know just what this circuit does and where to search for problems. Hope this helps. ( Note: don't confuse circuit or schematic diagrams with wiring diagrams; wiring diagrams will typically show pictures of elements like the pictorial, and how the entire or part of a circuit will be wired. The distinction is that wiring diagrams typically put an emphasis on actual physical place of necessary elements relative to each individual that essentially tell a layman Just What to do about the wiring. )