Venus is the second planet from the Sun and Earth's neighbour. In many ways it is very similar to Earth. The diameter is 95% of Earth's, both have relatively young surfaces.Their mass, densities and chemical compositions are also similar. It is believed that their interiors are very alike, ie. an iron core about 3000 km in radius with a molten mantle making up most of the planet's mass.
All of this might lead you to expect that Venus would be very Earthlike, however in other ways it is very different. Venus' atmosphere, composed mostly of carbon dioxide, has a pressure at the surface of 90 atmospheres. Clouds many kilometers thick, composed of sulfuric acid, cover the planet in a blanket many layers thick. There is a run-away greenhouse effect that causes a surface temperature of over 740 K (this hot enough to melt lead). Strong winds of up to 350 kph are present in the high atmosphere but surface winds are very slow. Any water that Venus once had has boiled awayIt is believed that mantle convection produces surface stress in many relatively small regions, unlike the Earth which has concentration at plate boundaries. Venus' surface is mainly rolling plains with 2 large highland areas, Ishtar Terra and Aphrodite Terra. There are also the depressions: Atalanta Planitia, Guinevere Planitia and Lavinia Planitia. The enormous Maxwell Montes are located on Ishtar. Most of the surface is covered by lava flows, but it is believed that with a few local exceptions, Venus is not very volcanically active now.
Venus' rotation is very slow, a Venus day is slightly longer than a Venus year. Venus' orbit is the least eccentric being almost circular. Venus has no magnetic field and it has no satellites.