What is rectangular marquee tool in PhotoShop?

You can use the rectangular marquee tool in many ways once you drag a marquee tool in workspace then right click then you have a lot of options but it t depends how you use that tool in creating a project.. It so very useful the basic part is for cutting and free transform or even transform that marquee tool. for advance you can create a stroke using marquee tool. refine the edge of subject. and etc.. marquee tool has a special functions in photoshop... :-) I love that tool..

are you just asking to pick points or what ??