Note. Unity 5 introduced the Standard Shader which replaces these shadersA program that runs on the GPU. More info See in Glossary.
These shaders are the basic shaders in Unity. They are not specialized in any way and should be suitable for most opaque objects. They are not suitable if you want your object to be transparent, emitting light etc.
One Normal mapA type of Bump Map texture that allows you to add surface detail such as bumps, grooves, and scratches to a model which catch the light as if they are represented by real geometry. See in Glossary