1. What differences exist between IGOs and NGOs (e.g. how can you tell them apart)?
Non-governmental organization (NGO) is an organization of general interest and does not belong to the Government nor to an international institution. It does not prevent it from cooperating or receiving assistance and funding from governments, it was founded without active control of a national government and it is a not-for-profit organization and are involved in every major international issue. If the organization activities go beyond the country's borders, it becomes an international NGO like "Doctors Without Borders", "Amnesty International" and "Human Rights Watch". On the other hand the Intergovernmental organization (IGO) is an international legal entity established by two or more States under an agreement between consenting, and aims to achieve goals and common interests in the following fields: political, military, social, economic, health, education and human rights. 
2. What does 'The Tragedy of the Commons' refer to?
An economic term used most often in relation to sustainable development, to link economic growth and environmental protection as well as in discussions about global warming. Garrett Hardin first introduced it in 1968 in an article in describing the need for individuals to adopt a positive change in their principles and behaviors. Tragedy of Commons, describes the state of depletion of a shared resource by individuals who share it independently and rationally, but