* *Principles*: a fundamental rule or concept in physics serving as a basis for reasoning.
* *Assumptions*: a less fundamental rule or concept in physics that is taken to be true such that certain phenoma can be simplified.
* *Definitions*: a precise and unambiguous description of the meaning of a physical term. It characterizes the meaning of a word by giving all the properties an only those properties that must be true.
* *Theorems*: a mathematical statement that is proved to be true using rigorous mathematical reasoning. In a mathematical text, the term theorem is often reserved for the most important results.
* *Laws*: a physical statement that is proved to be true, under the made assumptions and posed principles. In a physical text, the term law is often reserved for the most important results.
* *Proofs*: a convincing argument that a certain physical statement is necessarily true. A proof generally uses deductive reasoning and logic but also contains some amount of ordinary language.
The physics sections of this wiki are based on various books and lectures. A comprehensive list of references can be found below.