Is Fe(OH)3 a salt or an alkali?
Compounds do not class themselves as either one thing or another. Looking at a specific compound, there will always be classes that it is not, but save very few very simple compounds all will fit at least two classes.

$\ce{Fe(OH)3}$ is both a base and a salt. And a transition metal compound and a hydroxide and …

Let’s take an analogy. To some, I am a friend. To others I am a student. To others again, I am a teacher. I can be all of those, depending on who looks at me.