Use Selections to isolate an area of a photo in order to apply edits or filters to only that area, rather than the whole photo. There are
To Use a Selection 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.
Polygon: Click on any area of the image to begin the selection. As you move your mouse, the selection will follow your cursor. To change the direction of the selection line, click the left mouse button. Double-click to complete the selection.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 preview the selection mask by holding down the Preview button: 
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 preview the selection mask by holding down the Preview button: 
You can select an editing tool or a special effect to apply to the selection.
To Use the Rectangular or Elliptical Selection Tool:
, and drag another selection that includes any part of the original selection line. Release the mouse and the selection now includes the additional area.
, and drag another selection that intersects with the one you want to reduce. Release the mouse and any part that was inside the new selection is removed. You can preview the selection mask by holding down the Preview button: 
You can select an editing tool or a special effect to apply to the selection.
To Use the Polygon Selection Tool:
, and drag another selection that includes any part of the original selection line. Double-click and the selection now includes the additional area.
, and drag another selection that intersects with the one you want to reduce. Double-click and any part that was inside the new selection is removed. You can preview the selection mask by holding down the Preview button: 
You can select an editing tool or a special effect to apply to the selection.
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...
You can target selections to specific color tones and brightness values, as well as skin tones.
To Select Pixels by Color or Tone:
The Pixel Targeting Panel
The Pixel Targeting panel consists of four sections: Targeted Tones, Targeted Colors, Skin Targeting, and the Target Mask.
Target Mask:
The Target Mask allows you to see the areas in the image that are targeted by displaying them in white. When no pixels are targeted, the Target Mask will appear completely black. Conversely, when all pixels are targeted, as is the case before any sliders have been altered on the Pixel Targeting panel, the entire Target Mask will appear completely white.
Targeted Tones:
The Targeted Tones sliders allow you to target tones of brightness for selection. To target one or more tones, you may find it easiest to press the Min button under the Targeted Tones section. This deselects all tones, and you can then choose specific tones to target for selection by moving their sliders up between 0 and 100, depending on your desired intensity.
Targeted Colors:
The Targeted Colors sliders allow you to target specific colors for selection. To target one or more colors, you may find it easiest to press the Min button under the Targeted Colors section. This deselects all colors, and you can then choose specific colors to target for selection by moving their sliders up between 0 and 100, depending on your desired intensity.
Skin Targeting:
The Target Skin slider allows you to specifically target skin tones for selection. To target skin tones, move the slider to the right between 0 and 100, depending on your desired intensity.
When you move the Skin Targeting slider, all other colors, (except for skin tones), are excluded. You cannot then alter the green color slider, for instance.
To exclude skin tones from your selections, move the slider to the left between 0 and -100.