Parallax
![A simplified illustration of the parallax of an object against a distant background due to a perspective shift. When viewed from](/Images/godic/202501/18/Parallax_Example.svg2229.png")
![This animation is an example of parallax. As the viewpoint moves side to side, the objects in the distance appear to move more slowly than the objects close to the camera.](/Images/godic/202501/18/Parallax2229.gif")
![This image demonstrates parallax. The Sun is visible above the streetlight. The reflection in the water is a virtual image of the Sun and the streetlight. The location of the virtual image is below the surface of the water, offering a different vantage point of the streetlight, which appears to be shifted relative to the more distant Sun.](/Images/godic/202501/18/The_sun,_street_light_and_Parallax_edit2230.jpg")
![Parallax is an angle subtended by a line on a point. In the upper diagram the earth in its orbit sweeps the parallax angle subtended on the sun. The lower diagram shows an equal angle swept by the sun in a geostatic model. A similar diagram can be drawn for a star except that the angle of parallax would be minuscule.](/Images/godic/202501/18/Parallax_geo_or_helio_static2230.PNG")
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek word παράλλαξις (parallaxis), meaning "alteration". Due to foreshortening, nearby objects have a larger parallax than more distant objects when observed from different positions, so parallax can be used to determine distances.