Lasso Tool is also a selection tool with three different modes of selection.Set of Lasso tools is useful to select irregular portions of an image.
Click and hold your mouse for a moment on tool to open more options as shown
Lasso Tool
Lasso Tool is used to select free hand selection.
Click "Lasso Tool" and drag it over the portion of image like a closed path and release mouse.
Polygon Lasso
Polygon Lasso Tool is used to select areas in polygon shape.
Click "Polygon Lasso Tool" click at a point on the image. Click second point on the image.Clck third point......... finally double click the first point to complete selection.
Magnetic Lasso
Magnetic lasso tool is really very useful selection tool .When you drag around the image with this tool, it automatically start selecting complex portions of image . Lets see the real power of magnetic lasso tool.
Consider the example of this aeroplane:
Select "Magnetic lasso tool" from the toolbar.Clik at point marked "1" in the above image.Move your mouse counter clockwise to cover the portion of image of guitar.When you reach at point "1" just click at this point to complete selection .