The French and English dictionaries I have consulted translate "низкий" and "нижний" in ways that I find operationally indistinguishable.
Are these adjectives synonyms or is there a clear, unquestionable difference between them?
Edit
If I understand the answers correctly "нижний" would be a comparative or superlative of "низкий".
However all grammar books or online sites I consulted (for example this one) give"ниже", not "нижний", as the comparative form of "низкий".
And they don't indicate that the superlative is iregular.
In other words, "нижний" is never evoked in these grammatical explanations.
Does some user know a better reference on the subject ?