Push-Backs are illegal returns by the police that directly take place at the borders. If you ask for asylum the authorities are obliged to process your asylum procedure according by international laws. However, police at the border of many countries are pushing back migrants and sending them back without processing their asylum application. In some areas, there are bilateral agreements that even legalise the practice of push-backs. Police often beat up migrants, take their money, destroy their phones and send them further, outside of the European union.