The term "Vertical Axis" refers to a type of wind turbine that has its main rotor shaft arranged along a vertical axis. This means that as the blades spin, they do so in a circular motion around the central column or tower, with the axis of rotation being perpendicular to the ground. These types of turbines are also known as "vertical-axis wind turbines" (VAWTs) and can be used for both onshore and offshore applications. They have several advantages over traditional horizontal-axis wind turbines, including lower noise levels, reduced interference with nearby air traffic, and the ability to operate in low wind speeds. However, they also come with some disadvantages such as higher costs of production and installation, and a more complex design that can be affected by changes in wind direction.