Difference between internal and external doctoral studies in Germany
Keep in mind that most German PhD positions are not funded through "scholarships" but instead through standard labor contracts. Consequently, any listing of "scholarships" will likely include all forms of funding for graduate students. Filtering by internal or external positions will allow the database to select if you are being "employed" by either a university (internal) or a company (external).

There may be some nuances and particular issues depending on the school and faculty with respect to residence time, composition of your thesis committee, and format of the defense (among other issues) according to whether you're doing an interne Promotion or an externe Promotion. However, it's hard to say in advance if you'll run into this or not.