The paths tool is a tool where you select things but you have much more control because you can get every last detail in your selection. How you use this tool is you go into the toolbox window and click on the paths tool once you have drag your mouse over to where you want to start selecting. Once you are there left click to start and now the path will move with your mouse and you can click where ever you want to make more points. Once you are done you click on your first point again with the last point and a dotted line will start moving where you selected.