Yes, light waves can be described as traveling in straight paths called rays. When light propagates through a uniform medium, such as air or vacuum, it tends to travel in straight lines. This behavior is known as rectilinear propagation. Each individual line representing the direction of travel of a light wave is called a ray.
However, it's important to note that light can also exhibit behaviors such as reflection, refraction, and diffraction, which can cause the path of light to deviate from a straight line. These phenomena occur when light encounters a boundary between two different mediums, such as when it passes from air to water or when it reflects off a mirror. In these cases, the direction of the light wave can change, and its path is described using principles of optics. Nonetheless, the concept of rays is still useful for describing the direction of light propagation in many situations.