Describe the shapes of a concave lens and a convex lens

The fact that a double convex lens is thicker across its middle is an indicator that it will converge rays of light that travel parallel to its principal axis. A double convex lens is a converging lens. A double concave lens is also symmetrical across both its horizontaland vertical axis.
This is from google btw.

A concave lens ‘caves in’. A convex lens goes out like a bubble-shape. I don’t know of this will help, but use it if you can.

Magma  is composed of molten rock and is  stored  in the earth's crust. lava is  magma  that reaches the surface of our planet through a volcano vent.