The lasso tool consist of the Freehand Lasso Tool and the Polygonal Lasso Tool. These tools are used to make free-hand and polygonal selections of the active layer.
Using the ordinary lasso tool, simply click and drag a freehand selection with your mouse.
click to make various points which will define a selection, and finish your selection by clicking the starting point or pressing Enter key.
To move the selection, see Moving Region selections.