Photoshop Tutorials - Transform Selection
In addition to filling the selections with colors, there is an opportunity to transform the selection outline, changing its size and shape, and turning it at an angle.
To enable the transform mode go to Select > Transform Selection. A frame will appear around the selection outline and it will have markers at every corner and the middle of every side. By moving the markers, you can change the shape and size of the selection outline. Keep Shift pressed to make proportional changes. If you keep Alt pressed, the changes will be symmetrical, for example if you will pull the bottom side down, the top side will move to the top as well. When you keep Ctrl button pressed every marker becomes independent and you can transform the selection outline in any desired direction.
To turn the selection outline you will need to place the mouse cursor over any corner marker outside the frame.
To apply the changes made, press enter. Press Esc to cancel the transformation.
In order to move the selection outline you need to select one of the selection tools in Transform Selection mode and place it over the selection. When the arrow symbol will appear you can drag the selection to desired location on the image.
Transform Selection tool does not change the content of the selection; it just changes the selection shape and location. If you want to change the content of the selection, you will need to use Free Transform mode.