Free Transform

(shortcut on the keyboard is CNTRL or COMMAND + T)

modifications:

Holding down the Ctrl/Command key while dragging a middle handle allows you to skew the bounding box.

Holding down the Ctrl/Command key while dragging a corner handle allows you to distort the corners independently.

Holding down the Alt/Option key when dragging a corner handle resizes the bounding box from the center.

Holding down the Alt/Option key when dragging a side handle applies the transformation to both sides of the bounding box like a mirror reelection.

Shift constrains the movements and can be used in conjunction with the other modifier keys.

You can rotate the selection by moving the cursor just outside of a selection handle. The cursor will change to a double pointed arrow to indicate that you can rotate.

You can flip a selection by dragging one handle all the way across the bounding box to the other side.

To commit the transformation, double click inside the bounding box.

To reject the transformation, hit Esc.