A prominence is a red-glowing plasma, made up mainly of hydrogen and helium floating just above the surface of the sun. This gas sometimes becomes unstable and bursts outward. In this case it caused an explosion on the sun’s surface called a Coronal Mass Ejection. Thankfully, the sun spewed the charged particles away from earth, meaning scientists don’t expect a disruption to satellites and electronics here.
Find out more about solar storms and space weather here: http://www.nasa.gov/mission_pages/sunearth/spaceweather/index.html#q4