It's a solvent and a penetrating oil. It works for cleaning, getting something unstuck, or making sure something has no water on it (the "WD" is for "Water Displacement"). But it evaporates quickly and that's not good for anything you want to stay lubricated. It's okay for getting a rusty bolt moving because it's thin and easily gets where something thicker would not. It's not suitable for machinery that needs oil permanently on it. Also not good for locks, since it tends to gum them up.

In general if you need to lubricate anything important, you should look into what the official documents recommend. The right lubricant varies a lot depending on the application. Some stuff uses thin oils. Some uses sticky oils. Some wants grease. The right thing to use depends on things like manufacturing tolerances, the presence of oiling systems and the operating environment, so best to just check the manual.