Polygon filling is a technique used in computer graphics to fill the interior of a polygon with a particular color or pattern. To fill a polygon, it is necessary to determine the pixels falling on the border of the polygon and those which fall inside the polygon. There are different techniques to fill polygons, including the Scan Line Algorithm and the Flood Fill Algorithm. The Scan Line Algorithm is a method that fills the interior pixels of a polygon given only the vertices of the figure. The Flood Fill Algorithm is used when we want to fill the area and its boundary with different colors. The boundary fill algorithm picks a point inside an object and starts to fill until it hits the boundary of the object. The color of the boundary and the color that we fill should be different for this algorithm to work. The Scan-line Polygon Fill method is a fundamental graphics method used to fill closed polygons on a computer screen with a certain color. It is a basic computer graphics method that is used to display solid forms on a screen.