What are “Sunspots”?

Sunspots are areas seen as dark spots on the photosphere of the sun. Sunspots are concentrations of magnetic flux, typically occurring in bipolar clusters or groups. They appear dark because they are cooler than the surrounding photosphere. Sunspots vary on an eleven year cycle. Geomagnetic activity on Earth roughly coordinates with the sunspot cycle. The period of minimum sunspots usually means low geomagnetic activity on Earth.