Surface mounted technology - micro tracks (I didn't know the US used the term 'trace' - so thanks for that) Every componet is a teeny rectangular package that is stuck to the pcb and air jet soldered in place. Every component, though different is the same shape. An ordinary soldering iron tip is bigger than the component, let alone the solder tag. They are often very high density boards and while a paperclip wound around the soldering iron can sometimes fix them, I avoid them like the plague without a magnifying lens, special gear and a VERY stead hand. The PCB tracks can be 0.1mm thick - so the usual process of scraping off the green surface to reveal bright copper, then bridging the gap with a thin piece of wire and soldering each end is impossible. Jumping the break on a conventional board isn't too bad with good eyesight as the copper tracks are much, much wider. Doing it on SMT boards is awful, even for the experienced. If you need to look at a video, you won't be able to fix a SMT board. An ordinary board is far easier.
When you say a 'broken trace' - how broken, and how did it get broken? Flexing, physical damage, poor previous repair. They're not common as a fault, repairing these is usually because of damage. If you stick up a photo of the damaged area we can suggest how to do it, and what tools.