The verb schaffen
The verb schaffen has various meanings in different contexts.
Like “to achieve”, to have achieved a goal.
Markus hat die Prüfung bestanden. Er hat es endlich geschafft
Markus has finally passed the exam, at last he has succeeded
in fixed structures:
Die Kälte macht ihm zu schaffen
the cold is killing him
Markus ist total geschafft
Markus is totally exhausted
The verb erreichen:
as in “to locate”:
Sie können uns nach 20 Uhr unter dieser Nummer erreichen
You can reach us after 20 o’clock at this number
as “get” . In contrast to the verb schaffen, erreichen is rather used in contexts where the goal has not yet been achieved:
Wenn du etwas erreichen willst, musst du hart arbeiten.
If you want to achieve something, you have to work hard