Exchange semester in Cologne

A) How are academic courses in Germany structured?

B) What is a Fachhochschule - university of applied sciences?

C) What requirements must I meet to study at Cologne University of Applied Sciences as an exchange student?

D) What language skills must I have?

E) What if my home university has no contract with Cologne University of Applied Sciences?
in addition:
Explanation: What is Socrates/Erasmus?

F) Can I also attend the classes of a master's course as an exchange student?

G) How can I apply for an exchange?

H) How do I know if I have been accepted?

I) Must I enrol at Cologne University of Applied Sciences?

J) How are the courses structured?

K) Can I choose the classes I want to take myself??

L) Can I get financial support for studying in Cologne?

M) When does the semester start?