Use Selections to isolate an area of a photo to apply edits or filters to only that area, rather than the whole photo. There are three different selection tools and each selects an area of a photo in a unique way. The controls available change depending on which tool you select.
To Use the Selections Tool:
You can use Selections with the following Edit tools:
Freehand Lasso: Click the left mouse button and drag the cursor to draw around the area that you wish to select. As you draw, a line appears showing where you have drawn. When you release the mouse, the end of the line joins to the start automatically to complete the selection. The whole selection animates and looks like marching ants.
Magic Wand: Click on any area of the image and all the pixels the same color are included in the selection. You can choose whether to select only the same color pixels that are actually touching the one you clicked, or all the pixels in the photo that are similar. You can increase the threshold to include more pixels in the selection. The lower the threshold, the more similar a pixel has to be to the one clicked in order to be included. The greater the threshold, the more different a pixel can be and still be in the selection.
Rectangular or
Elliptical: Click and drag either a rectangle or an ellipse that begins where you first click and ends when you release the mouse.To Use the Lasso:

When you release the mouse, the original selection expands to include the outer edge of your addition.

As long as you do not touch the line of any other selection, you can add several separate areas to a selection.

Now the selection includes all the outside areas of the image with the central area outside the selection.
You can select an editing tool or a special effect to apply to the selection.
To Use the Magic Wand:
Color is generally your best option.
You can select an editing tool or a special effect to apply to the selection.
To Use the Rectangular or Elliptical Selection Tool:
You can select an editing tool or a special effect to apply to the selection.
You can right-click a slider to reset to the default value.
You can use the Selection tools separately or in combination. For example, you can use the Magic Wand to select most of a particular color, then switch to the Freehand Lasso to add to, or subtract from, the selection. Or you could use the Rectangular selection to select a large general area, then refine it using the Freehand Lasso.
To Combine Selection Tools:

Saving Selections as Presets:
You can save your settings as a preset for future use. After you have made a selection, click Select | Save Selection...
To use a previously saved selection, click Select | Load Selection...
To delete a saved selection, click Select | Manage Selections...