What is the Pen tool?
The Pen tool is a simple selection tool with a wide range of applications for users at every skill level. You can find the Pen tool in the lower half of the Photoshop toolbar, grouped with the Shape tool, the Type tool, and the Direct Selection tool.
Create a straight line by setting two anchor points. Add and move a third anchor point to create a curved line, or use the Freeform Pen tool to draw lines by hand. The marks you make with the pen tool are called paths.
To outline the path you created, right-click (for PC) or control-click (for Mac) on your path and choose the Stroke Path option. Then use the Color Picker to select a color. To fill a shape with a color, pattern, or gradient, choose the Fill Path option.
With the Pen tool you can trace the outline of one element of your image that you want to cut out or touch up separately.
What are paths?
One of the Pen tool’s most powerful functions is the ability to draw paths. When you use the Pen tool, you aren’t adding color to the canvas. You’re creating a line path which can then be used to make a vector shape — a flexible, scalable object.
Unlike pixel-based lines and shapes, which lose definition when they’re scaled up, a vector path maintains its sharp edges at any size. Every path you draw can be found in the Paths panel, where you can edit them individually or as a group.