This is a good question.

Structured programs are full-time programs for people who want to develop better skills in their doctorates, receive institutional support, and - if they get successful funding, also get support in planning and coordinating mobility phases from the institution. 

As part of a graduate school or research training group (or similar), early stage researchers take part in a program that differs from the traditional way in both its formal framework as well as the focus on better integration of doctoral researchers in a group and the wider academic community.