What are sunspots? Does it matter? Are strangely large sunspots cause for concern? Here’s more on sunspots from Astronomy Now:
Sunspots are temporary regions of intense magnetic disturbance where the energy from below is blocked by the magnetic force. This causes the area to cool down slightly compared to the surrounding surface creating the sunspots. If you look carefully, you will see there are two parts to a sunspot, a nearly black area called the ‘umbra’ (there may be several of these if the sunspot is extensive) with a much lighter region called the “penumbra”. Sunspots can be found on their own but quite often they come in groups which are then grouped into sunspot types depending on their extent and structure.
Sunspots occur over an average 11-year Sunspot Cycle and vary in number, size and structure of sunspots during that time. At Sunspot Minimum there are usually few if any sunspots for many days or occasionally for several weeks at a time. Gradually the number of sunspots begins to rise and their sizes increase. Some sunspots are occasionally big enough to be glimpsed with the eyes alone by looking through an eclipse viewer. After about three or four years we usually reach Sunspot Maximum when the Sun seems to never be without some sunspots. This situation persists for about two or three years and then the intensity of sunspots starts to fall away over the remaining years until we are once again back at Sunspot Minimum.