Once a selection has been made, it can be moved and transformed in a variety of ways.
If you have a selection in place, you can move and transform it, and the pixels it encompasses using the Move Tool or Transform Studio, respectively.
If you're looking to reposition a selection, but leave the pixel content untouched, you can use the Marquee tools. However, if you wish to transform your selection while leaving the pixel content untouched, you need to use either the Transform Studio or the Edit Selection as Layer option. In Quick Mask mode, you can resize, reposition, rotate or shear a selection using the Move Tool or Transform Studio.