Operating certificate is a category of license

License

The verb license or grant licence means to give permission. The noun license or licence refers to that permission as well as to the document recording that permission.A license may be granted by a party to another party as an element of an agreement...

 issued by a government agency

Government agency

A government or state agency is a permanent or semi-permanent organization in the machinery of government that is responsible for the oversight and administration of specific functions, such as an intelligence agency. There is a notable variety of agency types...

 allowing an individual or company to provide a controlled type of service. These certificates are generally issued for a limited time period. Certificates can have intrinsic value and in some cases can be sold.

The term can be used to describe the document issued to operate any of the following:

• Airline; (known as a Air Operator's Certificate
  Air Operator's Certificate
  An air operator's certificate is the approval granted from a national aviation authority to an aircraft operator to allow it to use aircraft for commercial purposes. This requires the operator to have personnel, assets and system in place to ensure the safety of its employees and the general public...
  
  ) the authority to operate an airline
  Airline
  An airline provides air transport services for traveling passengers and freight. Airlines lease or own their aircraft with which to supply these services and may form partnerships or alliances with other airlines for mutual benefit...
  
  
• Airport; in the United States, the authority to operate an airport
  Airport
  An airport is a location where aircraft such as fixed-wing aircraft, helicopters, and blimps take off and land. Aircraft may be stored or maintained at an airport...
  
  
• Adult care facility; generally issued by a local authority
• Transportation company; generally issued by a local authority