There are several types of student loans which vary in terms of either their funding purpose or financing model. The most common type is the classical student loan, the purpose of which is to provide general student financing. Then there are the so-called "education funds" (Bildungsfonds), from which funding is awarded to individually selected students. The advantage of this type of financing model is that the recipients are required to pay back a certain percentage of their future income after graduation – in other words, a low-risk model. And last of all, there are the so-called stop-gap, interim and follow-up financing loans offered by the Federal Office of Administration, the Studentenwerk, AStA at the University of Münster and the E. W. Kuhlmann-Stiftung. The purpose of such loans is to provide short-term financial assistance to students who are close to completing their examinations.
The most suitable and relevant model always depends on one's personal situation. The Student Advice and Counselling Centre (ZSB) can provide you with more information about education funds and student loans.
A good overview of all available models and their respective advantages and drawbacks is provided in the info brochure published annually by the Centre for Higher Education (CHE).