Principle is a modus operandi or a protocol produced for making a thing work. It is a law or a rule for doing things. At some places it is not mandatory to follow a principle and at some places it is inevitable otherwise the desired result will not be received. In every aspect of life or study, there are principles that are essentially followed by all. Whenever a principle is laid down for any specific effect, then it is the cause of that effect. When a principle is used as law, like in nature, physics or biology it is usually the observations that have been proved by experts and notable scientists.

Principles used as a scientific law are followed in that particular case, usually without any exceptions for attaining the desired result. When it is used as a moral law then it usually describes the set of rules a person must follow for ensuring a normal conduct in the society. Following moral principles is highly appreciated in the society and the person following it in all circumstances is highly respected by one and by all, while the person who doesn't follow moral principles is highly criticized.

There are laws as well, which are laid down in writing by the highest authority of the governing body. There are various principles that are used as logical fundamentals. For example:

• Principle of Sufficient Reason
• Principle of Identity
• Principle of Contradiction
• Principle of Excluded Middle.
• Logical Consequence

All these principles are considered as fundamentals and are followed in all the conditions. Principles are never contradicted because they are always accompanied by its proof and method of its derivation.

In physics, statistics and biology there are many principles that help in understanding the concept and arriving at conclusions. Such principles have been laid down by thorough research and understanding of the subject. Various experiments are conducted before finally concluding the result, which is fundamental for similar cases that may arise later.

These principles hold high importance and are imperative to study for understanding the subject in detail and mastering it. Almost in every subject area, whether it is economics or psychology, there are principles governing various concepts.

Just like the law of nature, which is the governing principle of nature around us there are several other laws and principles specifically for each subject and entity.