The specific contact found when a slide movement is performed with Rigidbody2D.Slide.
When a slide along a surface occurs, a surface contact will be detected either from using a Rigidbody2D.SlideMovement.surfaceAnchor or using Rigidbody2D.SlideMovement.gravityScale.
In short, if the movement anchors to a surface or if gravity causes a contact with the surface, this RaycastHit2D represents that contact.
NOTE: This contact does not necessarily represent the surface that movement is tangent to. That is represented by Rigidbody2D.SlideResults.slideHit.
See Also: Rigidbody2D.SlideResults.slideHit, Rigidbody2D.Slide and SlideMovement.