znajom / a = frżiend, aquaintence
Znajomy, znajoma = acquaintance
Koleżanka = girlfriend ( romantic interest )
Koleżanka = female colleague
przyjaciol /ka = VERY good friend sometimes known a finace / e
Przyjaciółka = friend (female), could be also a girlfriend, especially if is preceded by
myNarzeczona = fiancée (female)