This is a schematic diagram of a strato volcano, intended to illustrate the different layers of different materials that comprise them. The purple colors are meant to represent ashlayers, either the products of fall-out from big eruption clouds or the products of pyroclastic flows. Notice that these ash layers tend to be thin but widespread. The orange colors represent lava flows, and note that some of them have cinder cones associated with them at the vent. The green colors are meant to represent lava domes, and notice that they do not flow very far. Each eruption, regardless of what it produces, is fed from the magma chamber by a dike. Most dikes come up through the center of the volcano and therefore most eruptions occur from at or near the summit. However, some dikes head off sideways to feed eruptions on the flanks.