Sunspots are temporary phenomena on the surface of the Sun that appear as dark spots. They are caused by magnetic activity that inhibits convection, leading to cooler areas on the solar surface. These spots can vary in size and can last from a few days to several months. The number of sunspots fluctuates in an approximately 11-year cycle known as the solar cycle. During periods of high sunspot activity, solar flares and coronal mass ejections are more common, which can impact Earth's atmosphere and technology, such as satellites and power grids.