Founded in 1990 by former students in international mobility on the initiative of the Erasmus Bureau of the European Community, ESN is an international non-profit student organisation whose mission is to represent the interests of students in international mobility. Since 2010 ESN AISBL has been a full member of the European Youth Forum.

ESN operates at three levels: international, national and local and currently has about 350 sections in 36 countries. Its borders range from Iceland to Turkey, from Portugal to Lithuania, from Norway to Ukraine; more than 14,000 active members work as volunteers, providing services to about 150,000 students. The number of sections per country ranges from a minimum of one to a maximum of 40 (Italy). 

On an international level, ESN has regular meetings with authorities and international organisations to promote and discuss European student mobility and the needs of European students. The executive body of ESN International is the governing board, composed of 5 people. It is elected annually from among the active members of the associations and is based in Brussels. The national representatives of all NSE member countries form the Council of National Representatives (CNR), which is the consultative body of the Erasmus Student Network. The most important meeting is the Annual General Meeting (AGM), during which members of all sections make collective decisions about the future of the network. Finally, countries with a sufficiently large number of sections also have a National Board responsible for coordinating sections at country level. 

The sections work according to the principle of "Students helping students", in order to help exchange students to better enjoy their study experience abroad. They provide support to both outgoing and incoming students. Their members are mostly students who have gained an international exchange experience and want to make their knowledge available or students who are close to making an international exchange experience and who can acquire useful skills to face countries with cultural and social backgrounds different from their own through the individual sections.

Finally, ESN also provides an updated information service on European inter-university exchange programmes and develops a systematic evaluation of these programmes through the experience of participating students. From Brussels headquarters, ambitious projects are being developed such as ESN Survey, an annual study on the rights and problems of students participating in academic and non-academic mobility programmes; PRIME (Problems of Recognition In Making Erasmus), qualitative and quantitative research on problems in recognition procedures for studies abroad; ExchangeAbility, a project aimed at involving disabled students in ESN activities; SocialErasmus, to integrate foreign students through civic engagement in the local community; ESN Satellite, graphics used within the Erasmus Student Network for corporate design of websites and finally the ESNcard, used for membership within the network, which also gives the right to various advantages at local, national and international level.