They are dark patches on the photoshere. Sunspots are linked to the surface magnetic field of the sun. Sunspot group Sunspots usually appear in groups. Normally it is fairly easy to count the number of groups as they are spread out acrosthe disk and in both hemisphere.
Difficulties can occur when sunspots appear close together.
Then experience of different types of sunspot group can be used to determine the number of groups present. A single spot are a simgle compact cluster of spots with the greatest distance between the the two spots of the cluster not exceeding three heliographic degrees. Bipolar group Two spots or a cluster of many spots extending rougly east-west with the major axis exceeding a length of three degrees .