German ID cards have a chip in them. You can use your ID card and the AusweisApp to log into online government services. This is feature is called Online-Ausweisfunktion, eID, elektronischer Aufenthaltstitel or eAT.
Your German passport, Personalausweis and residence permit have this feature. This feature is not always activated. You might need to activate it at the Bürgeramt or at the Ausländerbehörde.