It’s one of those verbs turned nouns (validation) that is someone tricky to master.
When you’re little, you practice independence, you want to tie your own shoes, feed yourself, put your own clothes on, and parents encourage it because we need to learn to do things for ourselves. That independence though, you want recognition for; the first time you pee in the potty alone, you expect a Sesame Street parade down your block like that commercial. When you, as a child, paint, what you feel is an absolute work of museum worthy art, and your parents oooh and awwe over it so much that you are reaffirmed, your thought that it was beautiful is validated, and soon your frig is covered with scribbles and stick figures that, truth be told, only you truly view as art.
As you grow up though, having someone approve you, agree with you, support you, and even accept you can become somewhat dangerous if you fail to recognize when the transition occurs. I think there in lies the difference.
The healthy side of validation leans to, “do you share my opinion about what I’ve done, created, chosen, purchased, etc.?”, it’s external.
The unhealthy side leans to ‘prove to me that I am worthy, I am loved, I am good enough, and that you approve of WHO I am’, it’s internal.
That internal part is reserved only for you, that’s not a power you want to hand over to another person.