Selection tool are used to select a portion of image. With this portion allocated (selected) you can do what you want without affecting rest of picture.
See related link for detailed explanation with snapshots.
With Path Selection Tool you can select and edit individual anchor points from which path is constructed.
If you have a shape layer, or path created with the Pen Tool, it will let you select and edit individual points belonging to that path.
the masking tool
You can use the pen tool, quick selection tool and lasso.
Selections tools inside Adobe Photoshop are : Lasso tools, Marquee tools, Magic Wand and Quick Selection, Color Range from Select menu and you can also trace edges with Pen Tool or Magnetic Pen Tool which is accessible when Freeform Pen Tool is active.
Using selection tools from Toolbox: Magic Wand, Quick Selection tool, Rectangular and Elliptical Marquee tools...
There isn't drag tool in any Photoshop version. To move things around you can use Move Tool or Path and Direct Selection tools to move paths and shapes.
Quick Selection Tool creates selections by automaticaly detecting edges based on color and texture similarity of surounding pixels with clicked point. You can click or click and drag to create selection with Quick Selection Tool.
magic wand tool, quick selection tool, lasso tool polygonal or magnetic lasso tool. there the main one's.
Selection tools in Photoshop: Marquee Tools (M), Lasso Tools (L), Magic Wand and Quick selection (W). You can also select color from image as foreground or background color with Eyedropper Tool (I). Navigate with mouse above any tool in Photoshop and you will see tooltip with keyboard shortcut for that tool in parentheses.
For selections you can your the Marquee Tool, Lasso Tool, or Magic Wand Tool. To cut that selection you can use the Move Tool, or the Ctr-X keyboard shortcut.
Photoshop have Horizontal Type Tool and Horizontal Type Mask Tool which you can use to type text in Photoshop.
No Elements version have the pen tool. The vector features are limited, but the selection tools are very good, especially with version 14.
The tool is used to select specific locations/pixels on a picture. This is used to copy,create masking etc