"Flatlanders" refers to inhabitants of a two-dimensional world, as depicted in the novella "Flatland: A Romance of Many Dimensions" by Edwin A. Abbott. In this fictional universe, the characters are geometric shapes, such as squares and triangles, living in a flat plane where they can only perceive length and width, but not height. The story explores themes of dimensions and perception, illustrating how limited viewpoints can restrict understanding. The protagonist, a square, encounters a three-dimensional being, which challenges his understanding of reality and encourages readers to consider the possibility of dimensions beyond their own.