The Benelux consists of the Netherlands, Belgium and Luxembourg. It was founded in 1958 as a means to promote cooperation between the member states.
The European Union (EU) has 27 member states. It was founded in 1951 to promote economic cooperation between the member states. Between the member states, free traffic of goods, services, persons and work exists. The EU operates on a great number of topics. Its currency, the Euro (€), is legal tender in the Eurozone. The Netherlands is also a member of the EU Taxation and Customs Union, the division that enables free trade of goods within the EU.
The Schengen area comprises most EEA members (minus Bulgaria, Croatia, Cyprus, Ireland, Romania, and the UK), plus Switzerland. It is an area within which citizens, many non-EU nationals, business people and tourists can freely circulate without being subjected to border checks.
The European Economic Area (EEA): this consists of all EU countries and of Liechtenstein, Iceland and Norway.
The Council of Europe was founded in 1949. With 47 member states, it is Europe's leading human rights organisation.
The EU also has a monetary agreement with the states Monaco, Andorra, San Marino and Vatican City, meaning the Euro can be used as legal tender in those states.
You will find a list of all Schengen - EU - EEA member states on the Netherlands and You website.
Other alliances
The organisations mentioned above are the ones the Netherlands are part of. These are the European alliances the Netherlands does not participate in: