I read this word in many threads written by posters.
Not only by word but also by behaviours, reactions…

I’m being very honest, as I am often, when asking what these people mean with validation.
I ask this question because I don’t find any sense to ask for such a thing, but the reality is such.

From Oxford dictionary:
Validation “ recognition or affirmation that a person or their feelings or opinions are valid or worthwhile. “

And what happens if you find replies in a different sense?