Positive law is a law that was generated by humans through legislation. This is the opposite of natural law, which is when something is inherently true (such as the law of gravity).
Positive law covers all legislation and case law that exists regarding all subjects. The combined laws, which govern people in all aspects of life, are referred to as positive laws because they have been written for the purpose of creating a positive effect.
The term "positive law" is quite general and can be defined slightly differently at times. At its core, it refers to regulations that were enacted by people. It is considered a benchmark of an organized society.