What best describes a line in geometry?

A line in geometry is defined as a set of points that extends indefinitely in both directions. This definition emphasizes that a line has no endpoints; it continues forever without stopping. It has a length but no thickness, and it can be represented visually by a straight path connecting any two points along it, but its nature is such that it continues endlessly beyond those points.

The concept of a line is foundational in geometry, allowing us to build more complex shapes and forms, such as angles and polygons, by connecting lines in different ways. Understanding that a line is infinite helps in various mathematical applications, including graphing linear equations and solving geometric problems. Thus, the correct characterization of a line takes into consideration its infinite extent, differentiating it from other geometric figures that may have defined boundaries or limited dimensions.