If you’ve been around the (electronics) DIY scene for a while, at some point you can’t avoid circuit boards (printed circuit boards/PCBs). The main advantages over soldering circuits by hand on perforated or strip-grid boards are that they are easier to replicate (once designed a circuit can theoretically be produced as often as you like) and that space can be used more efficiently (a board is almost always smaller than a soldered perforated grid board with the same circuit). Ultimately, devices with circuit boards also simply look more professional. There are certainly more advantages (and of course also disadvantages!), but I will not list them here for the sake of simplicity.
Self-built UV exposure unit (LED)
