Euclidean geometry is named after the infamous Greek mathematician Euclid of Alexandria, often referred to as the Father of Geometry. Very little is known about his life, but his most famous work — The Elements, a collection of 13 books — has been recognized for countless generations until now. Put simply, Euclidean geometry is the study of points, lines, planes, and other geometric figures.
In the 19th century, some mathematicians introduced new kinds of geometry: hyperbolic and elliptic. Together with Euclidean geometry, they complete all possible geometries in the two-dimensional plane. Of course, we would never touch hyperbolic and elliptic geometry in the upcoming articles.
Image by Cmglee — Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=94781281