Non-Extensive Self-Consistent Thermodynamic Theory (NESCT) is a scientific theory that explains the behavior of different kinds of materials at very different temperatures. It does this by looking at the 'rules' that come from thermodynamics (the study of heat and energy). NESCT looks at how the rules of thermodynamics can be used to explain some materials that don't fit the classic thermodynamic rules. To explain this, imagine different materials as piles of blocks of different sizes, stacked in different ways. With NESCT, scientists can identify how the blocks fit together, and what kind of 'rules' govern them. Doing this can help explain why certain materials behave differently to others when temperatures change.