One-sided PCB board: The solder joints are concentrated on one particular side, and components are usually inserted on one other aspect. Some products still have SMD components over the copper-clad aspect. Double-sided board: Either side might be layout, and both of those may have plug-in components or SMD components. In https://mylesjnppq.angelinsblog.com/30646573/the-2-minute-rule-for-double-sided-low-power-pcb-circuit-board