The -ski ending
Many Polish surnames end in -ski (or -cki), historically meaning “of” or “from” a place, and once associated with the nobility (szlachta) who took their names from their estates — Zieliński “of the green place,” Kamiński “of the stony place.” The feminine form ends in -ska: Kowalski, but Kowalska.
Occupations and patronymics
Others come from trades (Kowalski, “smith”; Krawczyk, “tailor”), from a father’s name (Szymański, “son of Szymon”), or from nature and nicknames (Nowak, “the new one”).