Basic tax-free allowance
In German: Grundfreibetrag
The basic allowance makes all income up to a certain amount tax-free; based on the subsistence level (minimum amount of money a person needs to live) in Germany. This amount can potentially change each year.
For the tax year 2020, for instance, the basic tax-free allowance is 9,408 Euros for singles and 18,816 Euros for married couples or life partners.