This picture was taken near the height of the sun's 11 year cycle, and more sunspots are visible here than normal. Each spot has an inner dark umbra surrounded by a half shaded penumbra. The largest sunspot in the upper right of the main image is approximately 50,000 miles across, which is 6 times the diameter of the Earth. An enlarged view of that sunspot is presented on the right. Sometimes a spot lasts only for a few hours, but very large spots occasionally grow and last for weeks or months.
Sunspots usually appear in pairs, as can be seen here.
Sunspots are indicators of small twisted loops in the sun's magnetic field. The photosphere's granular appearance is apparent in this photo. Picture was taken from a blacktop parking lot, which probably degraded the image somewhat.