The Common European Framework of Reference for Languages (CEFR)
A1 Communication in basic language
A2 Everyday conversations on familiar topics in simple language
B1 Effective communication about everyday topics
B2 Active participation in discussions on different subjects
C1 Effective communication about complex topics, only occasionally unsure
C2 Fluent or near-fluent use of language even in complex situations
Online placement tests (German language only) for German, English, Italian, French and Spanish can be found on the pages for those languages.