Selection Tools > Marquee Tools

You can use the selection tools to select certain areas of your document for editing. If you use a selection tool.

Marquee Tools
1.Rectangular Marquee Tool (M)
Use this tool to make selections on your image, in a rectangular shape. This changes the area of your image that is affected by other tools or actions to be within the defined shape. Holding the [Shift] key while dragging your selection, restricts the shape to a perfect square. Holding the [Alt] key while dragging sets the center of the rectangle to where your cursor started.

2. Elliptical Marquee Tool (Shift + M)
Use this tool to make selections on your image, in a Elliptical shape. This changes the area of your image that is affected by other tools or actions to be within the defined shape. Holding the [Shift] key while dragging your selection, restricts the shape to a perfect rounded shape. Holding the [Alt] key while dragging sets the center of the rectangle to where your cursor started.

Another two selection tools like that Single Row Marquee Tool, Single Row Column Tools it selections only single lines.