If I remember Solidworks provided a small booklet in which you could find all the icons used with their definition (like the drapeu of on constraint, the little + etc ...).
Does anyone know if it still exists maybe in the help but I can't find it.
If you right-click on your icon bar from SW, then customize, check that you have "tooltips" checked, this gives you the definition of your icons when you hover the mouse over your icons.
In addition to the answers above, you can download a document (admittedly a little dated) from myCADservices. But with order finders, you shouldn't need them anymore!