The volunteering services that you may do via the Austrian Service Abroad are 3 types:
Gedenkdienst: Remembers the atrocities of Nazism and commemorates its victims. Gedenkdiener work at places of Holocaust commemoration, museums, research institutes and organizations supporting Jewish culture and life
Social Service: Austrian Social Servants collaborate within the framework of international development assistance in diverse social projects around the word. Social servants work in the fields of education, support of people with special needs, environmental protection, medicine, economic development and infrastructure building
Peace Service: Austrian Peace Servants collaborate in projects of peace-building, peace-pedagogics, women's rights, reconciliation and the commemoration of atrocities other than the Holocaust
Further information about the types of service you may find here. Please note that the specific tasks strongly vary from partner organization to partner organization.