Cinder cones are simple volcanoes which have a bowl-shaped crater at the summit and only grow to about a thousand feet, the size of a hill. They usually are created of eruptions from a single opening, unlike a strato-volcano or shield volcano which can erupt from many different openings.
They are usually made of piles of lava, not ash. During the eruption, blobs (“cinders”) of lava, blown into the air, break into small fragments that fall around the opening to the volcano. The pile forms an oval-shaped small volcano, as shown in this picture.
Famous cinder cones include Paricutin in Mexico. Another well known cinder cone is in the middle of Crater Lake.
source windows to the universe, USGS aerial photo – SP crater cinder cone . http://geology.com/volcano/sp-crater.shtml