The Internet packages are designated by their speed, e.g. "Internet Package VDSL 100". This package allows the top download speed of 100Mbit/s (Download means getting data from the Internet to my device) and upload speed of 20Mbit/s (Upload means getting data from my device to the Internet).
The address checker might deliver a result such as this:
Max Download speed: 40 Mbit/s
Max Upload speed: 16 Mbit/s
This is the actual technically feasible speed at your location.
Both the "Internet Package VDSL 100" and the "Internet Package VDSL 50" would work at this location. But with the "Internet Package VDSL 50" you would have the Upload speed of 40Mbit/s, but only the Upload speed of 10Mbit/s instead of the maximally possible 16Mbit/s.