What Is Difference Between Line and Polyline in AutoCAD?

What Is the Difference Between Line and Polyline in AutoCAD?

When working in AutoCAD, it’s important to understand the different types of objects you can create. Two commonly used objects are lines and polylines.

While they may seem similar at first glance, there are significant differences between the two. In this article, we will explore these differences and highlight when to use each one.


A line in AutoCAD is a simple and straightforward object that connects two points. It is represented by two distinct endpoints.

You can create a line by specifying its start and end points, or you can draw it by clicking on the screen. Lines are generally used to represent straight segments or boundaries.

Here are a few key characteristics of lines:

  • Straightness: Lines are always straight and cannot be curved.
  • Individual Entities: Each line is treated as a separate entity, which means they do not share properties or attributes with other lines.
  • No Width: Lines have no width or thickness; they are considered infinitely thin.
  • No Area: Since lines have no width, they do not enclose an area.


A polyline, short for “polygonal line,” is a more versatile object that consists of one or more connected line segments. It can be thought of as a series of lines joined together to form a continuous shape. Polylines can be open or closed.

Here are some important aspects of polylines:

  • Multiple Segments: A polyline can have multiple line segments, allowing for both straight and curved sections.
  • Shared Properties: All segments of a polyline share the same properties and attributes, such as color, linetype, or thickness.
  • Width and Area: Unlike lines, polylines have width and can enclose an area. The width is controlled by the lineweight property.
  • Editing Capabilities: Polylines offer additional editing capabilities, such as adding or removing segments or changing segment types.

Choosing Between Lines and Polylines

The choice between using lines or polylines depends on the specific requirements of your drawing. Here are some scenarios where one might be more suitable than the other:

  • Straight Segments: If your design consists of only straight line segments, individual lines may be sufficient.
  • Curved Segments: When dealing with curves or arcs, polylines allow you to create smoother shapes without the need for multiple individual lines.
  • Filled Areas: If you need to represent areas with filled colors or hatching, polylines are necessary as they can enclose an area.
  • Efficiency: Using a single polyline instead of multiple lines can improve efficiency in terms of file size and editing operations.

In conclusion, while both lines and polylines serve a similar purpose in AutoCAD, they differ in terms of complexity and functionality. Lines are simple straight segments with no width or area, while polylines offer the ability to create more complex shapes with width and enclosed areas. Understanding these differences will help you make informed decisions when creating your drawings in AutoCAD.