This is a wonderful little tool that you can use instead of some of the buttons in your toolbar. However, this box is really not necessary, as most of this can be found in your toolbar under "Tools", as shown below:
This is what your "Tools" box look like:
Let's start with the left side, working down:
Rectangle Select: for use in cropping your images -- it uses a rectangle in which you can crop out a section of any photo you wish to have cropped. (It can also be used with photo effects, stretching and moving selected pixels, see below.)
Using the Black & White Effect: Highlight the selected area with your cropping tool. Go to Adjustments > Black and White. Only the selected INSIDE of your area will turn black and white.
Stretching: Once you've selected your area with the cropping tool, grab any of the little nubs you see around the area. There are four -- one on each side of the image.
Lasso Select: is another cropping tool, but just not in a rectangle. It takes the shape of a lasso, like it claims. Just click on your image and drag to go out in a circular motion.
Ellipse Select: is a cropping tool but is great if you want to make a complete circle of any size from an image.
Magic Wand: is great for when you wish to delete a colour of your choice. If you have a black background and wish to eliminate it, you would select the magic wand in your toolbar and left click to select the area. Then, hit delete on your keyboard to "erase" it from your image. You can also hold CRTL while clicking on several areas to "erase" more than one area.
When you bring up your magic wand, you'll see the settings for it in your upper toolbar. It automatically on "replace", I never change this. But you can lower or increase your Tolerance levels, depending on how well the magic wand deletes an area.
Paint bucket: allows you to "dump" or "drop" or "flood fill" a white or PNG background with your colour of choice from your colour wheel. Choose your colour, left click on your background and it will "flood fill" it with your colour.
Paint brush: allows you to use brushes of different sizes to colour in smaller areas of your project. Just left click your mouse and drag to fill your area.
You can change how the paintbrush will fill by changing the drop down menu below. For full colour, leave as is. When using a different fill style, it will use both primary and secondary colours.
Pencil: is a drawing tool that I don't use at all. Great if you want to make freeform lines.
Clone Stamp: is a tool that will take a small section of a photo and use that image to cover up something you want out of your image. I'm not very good at this.
Text: is how you will add text to your tag, but you can also grab this under "Tools" in your toolbar.
Rectangle: not sure what this does, as I do not use it. Known to be able to make rectangle shapes.
Ellipse: does pretty much the same thing as Ellipse Select, except this just makes the shape.
Let's start now with the right side, working down:
Move Selected Pixels: used as a moving tool.
You can move a whole image, as seen below:
Once you've cropped your image, you can move it to another location on the same photo, as seen below. Just crop, use "move selected pixels" in your toolbar, left click in square and move!
Move Selection: helps you to move your elements on your canvas.
Zoom: gives you the ability to make your image far away or close up, for better viewing.
Pan: gives you nubs in order to grab to make your image bigger or smaller. Not recommended because this can make your elements blurry and odd shaped. (Use Resize instead.)
Gradient: gives you the ability to make a rainbow of colours for backgrounds. It can combine two colours so that they "slide" from one colour to another. It can take one colour of choice into a transparent condition. Or, it can fade out an image or photo by the choice of Mode you use. Modes are as follows (and in order: Linear, Linear Reflected, Diamond, Radial and Conical):
Eraser: helps you to erase anything from your creation.
Colour Picker: helps you to grab a colour from any image or element and then use that colour to re-colour another object. To use, just place your cursor on any colour you see, left click your mouse, and the colour will show up in your colour wheel.
Recolour: allows you to pick a colour and use it to recolour an image or element.
Line/Curve: helps you to create lines and curves.
Rounded Rectangle: help you to crop in a round rectangle style.
Freeform Shape: allows you to control your crop shape.