  Since the cuprate materials behave many curious properties, the mechanism
that causes high-temperature superconductivity in copper oxide materials
(cuprates) has been a controversial topic. To explain these curious properties,
we must look out the physics what these materials include. In this letter, it
is presented that there are the basic physics (1)-(9) in solid materials. I
divide all solid materials into four categories, explain some properties of
them qualitatively, and suggest some ways to turn a solid material into a
superconductor. Particularly, this letter discusses the differences between the
p-type high-Tc cuprate superconductors, the n-type superconductor Nd2-xCexCuO4,
the BCS-superconductor similar MgB2, and heavy Fermions superconductors.
