What are sunspots?

Sunspots are regions of the Sun, with less temperature than the rest of the solar surface. In addition, they have a high magnetic activity.
The absence of sunspots has a negative effect on the propagation of electromagnetic waves, causing broadcast transmissions, especially in short waves, to be affected and become unstable.
I like amateur radio (radio amateur), I notice in the low possibility of contacts with distant stations.
We are currently in the SS observation cycle 24, since it began to carry a data about 250 years ago.
The cycles of SS. Have an average duration of about 11 years. 
Compare the size of the Earth with that of a sunspot, in the graphic above.