Venus is often referred to as Earth's "sister planet" due to its similar size, mass, proximity to the Sun, and bulk composition. Both Venus and Earth are similar in terms of their size, with Venus being only slightly smaller. They also have comparable densities and chemical compositions, suggesting they formed under similar conditions. However, despite these similarities, Venus and Earth have evolved very differently, especially in terms of their atmospheres and surface conditions. This comparison provides valuable insights into planetary evolution and the factors that lead to habitability or inhospitable conditions.