Legal drinking age. The legal drinking age is the age at which a person can legally consume or purchase alcoholic beverages. These laws cover a wide range of issues and behaviors, addressing when and where alcohol can be consumed.
An open system is a system that has external interactions. Such interactions can take the form of information, energy, or material transfers into or out of the system boundary, depending on the discipline which defines the concept.
Allowing a system to be open ultimately sustains growth and serves its parent environment, and so both have a stronger probability for survival. Examples of open systems: Business organization, Hospital system, College or University system. Conversely, a closed system is more prone to resist incorporating new ideas, that can be deemed unnecessary to its parent environment and risks atrophy. By not adopting or imps, a closed system ceases to properly serve the environment it lives in.