An isolated system with no interaction or interface with any external environment. Recognizing a closed systems externally comes only from its outputs that are not dependent on the system being closed or open. Closed systems without outputs are visible only to those who are a part of the system. Refer also to entropy.

• RELATIONAL DATABASE
• RELATION BACK
• RELATION OF EARNINGS TO INSURANCE
• RELATIONSHIP
• RELATIONSHIP
• RELATIONSHIP BANKING
• RELATIONSHIP BANKING
• RELATIONSHIP MARKETING
• RELATIONSHIP MODEL
• RELATIVE
• RELATIVE ADVANTAGE
• RELATIVE CONVENIENCE DOCTRINE
• RELATIVE FACT
• RELATIVE MARKET SHARE
• RELATIVE PRICE
• RELATIVE PURCHASING POWER PARITY
• RELATIVE RIGHTS
• RELATIVE URL
• RELATIVE URL
• RELATIVE VALUE
• RELATIVE VALUE
• RELATIVE VALUE SCHEDULE
• RELATIVE VALUE SCHEDULE
• RELATIVE VALUE UNIT
• RELATOR