Making and Using Selections in PS:
A selection is an area of a photo that you define.
When you create a selection, the area is editable (for example, you can lighten one part of a photo without affecting the rest).
Above: I've used the Quick Selection Tool to select just the basketball in the photo.
You can make a selection with either a selection tool or a selection command.
A selection border surrounds the selection.
You can change, copy, or delete pixels inside the selection border, but you can’t touch areas outside the selection border until you deselect the selection.
Above: I've changed the colour of the basketball in the photo to be pink and then deleted it from the image altogether
Video Resources on the different "Manual" Selection Tools in Photoshop:
Photoshop Tools Tutorial | Lasso Tool, Quick Selection, Magic Wand and More
How To Use The Quick Selection Tool to Cut Out Images
How To Use The Lasso Tool To Cut Out Images