When you are defining layers, linetypes provide another way to convey visual information.
A linetype is a repeating pattern of dashes, dots, and blank spaces you can use to distinguish the purpose of one line from another.
The linetype name and definition describe the particular dash-dot sequence, the relative lengths of dashes and blank spaces, and the characteristics of any included text or shapes.
To assign a linetype to a layer, use the Linetype property. This property takes the name of the linetype as input.