A schematic diagram refers to a specific kind of circuit design that uses standard electrical/electronic symbols rather than images to demonstrate how a circuit (or a part of it) works. Below is a typical 3-wire motor controller circuit utilizing a standard momentary stop - start pushbutton station working with a schematic diagram. (Momentary here means that the button/switch you trigger will go back to its default place once you physically let go of this, typically by a spring which forces the button/switch to do this.)
Consider it in this way; a circuit diagram is any kind of diagram which demonstrates how a circuit operates where the main objective is the appropriate wiring of components and their relationship to each other rather than physical place relative to one another or intending prototypes. However, in some applications classifying diagrams can be challenging so consider this as overall advice. I have discovered this is particularly true when working with much more complex circuits and electronics. I'm likely to use a simpler but average industrial circuit since these circuit set ups are exactly the same, but where you're able to see how each type of diagram indicates the role of the circuit in their own ways.
Here's another schematic diagram demonstrating precisely exactly the same circuit, components and connections and it seems different but they fall into the same category.
Pictorial schematic diagrams, or pictorial circuit diagrams are basically the exact same thing with the identical purpose, however they use images of components within the circuit rather than symbols. Again, here's the exact specific circuit (virtually except a controller was included and they're using conductors L1 and L3 rather than L1 and L2.
Here's a version of a diagram called a ladder structure. The principle point of this diagram is to show the logic (referring to electrical management ) of a circuit. This really is the one that I mainly encounter in my own line of work, and it is extremely effective for troubleshooting issues or learning how a circuit works. Some frequencies are so huge that many kinds of schematic diagrams have to be recorded in increments from book form (usually with coded numbers so info can be simpler found). Again, here is the exact specific circuit because the first two weeks, however, considering it in ladder shape.
Right, much less clutter? I've got enough information in every one these diagrams to know just what this circuit will do and also where to start looking for problems. Hope this helps. ( Note: do not confuse lecture or circuit diagrams with wiring diagrams; wiring diagrams will typically show pictures of elements like the pictorial, and also how the whole or part of a circuit is wired. The distinction is that wiring diagrams typically put an emphasis on real physical location of necessary components relative to each other that basically tell a layman exactly what to do concerning the wiring. )