Photoshop Tutorials - Free Transform
Photoshop provides you with an opportunity to move the selection and its content. You move selections by applying the Move tool to them. When the selection is moved, there will be the hole in the image. If you want to move the copy of the selection, while it remains where it was, you need to keep Alt button pressed when using the Move tool.
In addition to filling the selections, there is an opportunity to transform them- change the size, shape and turn them at any angle. The tool that lets you perform these changes is a Free Transform tool. You can enable it by going to Edit > Free Transform or by pressing Ctrl+T hotkey.
Free Transform tool works similar to Transform Selection tool. A frame will appear around the selection and it will have markers at every corner and the middle of every side. 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 in any desired direction. To turn the selection you will need to place the mouse cursor outside the frame until the respective symbol will appear by the cursor.
Note: To apply the changes made you MUST press enter. Press Esc to cancel the transformation. Until you have pressed Enter, not other changes can be made.