Selections are used to edit specific areas of an image, and there are many ways to make them in Photoshop.
These dotted lines, also known as marching ants, show the selection boundaries.
That means you can paint or apply an edit, and it's only going to impact the pixels inside the selected area.
For simple geometric selections, use the marquee tool.
To draw freehand selections, try the lasso tool.
To choose an object, try object selection and make sure detect objects is toggled on.
Photoshop will analyze the image and a series of thumbnails will appear, breaking out each object.
Click on a thumbnail to select the object in the image, or hover over different parts of the image directly on the canvas, then click the object to select it.
Once defined, selections can be easily expanded, contracted, or even used to create a layer mask.
In fact, you can use a selection to completely remove something from your image like this.
And that's a quick look at a few of the selection options in Photoshop.
