If you see something like A1, B2 or C1, these represent the proficiency of a speaker in a language they're not native in, and are called CEFR levels. They are valid for any language, not only German!
Roughly speaking, A levels are beginners and C levels are experts. Remember that CEFR level are self-assessed and indicative!
You can see more specific names and descriptions on the Wikipedia page:
https://en.wikipedia.org/wiki/Common_European_Framework_of_Reference_for_Languages
🗨 How do I know what level I am?
If the table on Wikipedia is too generic for you, you can try using this one here:
https://rm.coe.int/168045bb52
Just check each column one at a time: if you can do all it describes, move to the next column. Your level is the highest where you can do the most things.
Alternatively, you can use this questionnaire to estimate your level more accurately:
https://www.laits.utexas.edu/fi/sites/laits.utexas.edu.fi/files/Self Assessment Checklist European.pdf





(21217 uses, 11%, 64.36 uses/day)
(17267 uses, 9%, 52.38 uses/day)
(11883 uses, 6%, 36.05 uses/day)
(8960 uses, 5%, 27.18 uses/day)
(8896 uses, 5%, 26.98 uses/day)
(8307 uses, 4%, 74.36 uses/day)
(8023 uses, 4%, 24.34 uses/day)
(5167 uses, 3%, 15.67 uses/day)
(4631 uses, 2%, 22.05 uses/day)
(4535 uses, 2%, 13.76 uses/day)
(2731 uses, 6% 8.28 uses/day)
(2062 uses, 4% 6.25 uses/day)
(87 uses, 8%, 0.31 uses/day)
(42 uses, 4%, 0.13 uses/day)
(40 uses, 4%, 0.12 uses/day)
(481 uses, 6%, 1.46 use/day)
(268 uses, 4%, 0.81 uses/day)
(234 uses, 3%, 5.61 uses/day)
(201 uses, 11%, 15.05 uses/day)
(12 uses, 4% 0.14 uses/day)



(53 uses, 13%, 0.16 uses/day)
(13 uses, 3%, 0.04 uses/day)
(6 uses, 6% 0.02 uses/day)
(940 uses, 15%, 2.85 uses/day)
(687 uses, 11%, 2.08 uses/day)
(229 uses, 4%, 0.69 uses/day)
(15 uses, 12% 0.05 uses/day)
(9 uses, 7% 0.03 uses/day)
(5 uses, 4% 0.02 uses/day)

(1 use, 8%, 0.0 uses/day)
(1 use, 8%, 0.0 uses/day)
(1 use, 8%, 0.0 uses/day)
(1 use, 8%, 0.0 uses/day)
(1 use, 8%, 0.0 uses/day)
(1 use, 3% 0.0 uses/day)
(586 uses, 47%, 1.78 use/day)
(50 uses, 4%, 0.15 uses/day)
(14 uses, 1%, 0.04 uses/day)
(9 uses, 1%, 0.03 uses/day)
(2 uses, 4% 0.01 uses/day)
(25 uses, 3% 0.08 uses/day)
(16 uses, 3% 0.38 uses/day)
(15 uses, 3% 0.05 uses/day)
(89 uses, 10%, 0.27 uses/day)
(83 uses, 10%, 0.25 uses/day)
(32 uses, 4%, 0.16 uses/day)
(30 uses, 4%, 0.11 uses/day)
(5 uses, 5% 0.02 uses/day)
Text: 68 (31 locked)
Voice: 12 (3 locked)
73194
Level 3 (25 boosts)
(12 uses, 2%, 0.06 uses/day)
(11 uses, 2%, 0.03 uses/day)
(1 use, 100% 0.01 uses/day)