Disability is defined as a limitation of physical, psychological or mental ability that lasts longer than six months and prevents a person from living a life typical of their age. Disabilities include not only physical and mental conditions but also chronic illnesses (such as rheumatism, multiple sclerosis, cancer) and mental illness.
There are several degrees of disability (in German: "Grade von Behinderung" or "GdB") ranging from 20 to 100. The higher your GdB (i.e. the harder your disability), the more support you receive from the state. Your doctor will determine what your GdB is.