Window glass, display device including the same, and method of manufacturing a display device

A window glass includes a first surface and a second surface opposite to the first surface. A second area extending in a second direction, a third area spaced apart from the second area in a first direction perpendicular to the second direction and extending in the second direction, a first area disposed between the second area and the third area, a first buffer area disposed between the first area and the second area, and a second buffer area disposed between the first area and the third area are defined on the second surface. The first area has a first thickness, and each of the second and third areas has a second thickness greater than the first thickness. A plurality of groove patterns is defined in the first buffer area and the second buffer area.