First, for the single-sided pcb, parts focused on one side of the wire is concentrated on the other side. Because the wire only in one side, so we call this PCB as single-sided circuit boards. Usually when produce single-sided pcb board, its advantage is low cost and easy job while it’s disadvantage is not suitable for too complex products.
Hole (Through hole / via): vias allow two levels above each line is turned on, the larger the vias used as a plug-in parts. Then another non-conductive hole (nPTH) is usually used as a surface mount loaded position when assembled fixing screws.
Solder Mask (Solder resistant / Solder Mask): It’s no need to eat tin copper surface on all parts, so on the non-food area of tin, copper will be printed on one side eaten tin isolated substance(usually an epoxy resin),avoid non-food tin between short-circuit. Depending on different process, it divided into green oil, oil, oil blue.Screen printing (Legend / Marking / Silk screen): This is not a necessary structure, its main function is to mark the label name, the location of the box on the board, which is helpful to repair and identify in the later need.