Approval means, “I condone or sanction or endorse you or this thing you are doing.”

Approval has an official ring to it. We use it in legal language and corporate language.

“The bill was approved by Congress.”
“The merger was approved by all parties.”

To approve or to sanction is to authorize.

Approval can only come from someone who is in a position of authority over someone else.

Sometimes this is okay.

For example, if I apprentice myself to a master craftsman — say, a chef — I do so with the understanding and acknowledgement that this chef is superior to me in their knowledge and skill in cuisine. I choose to place myself under the authority of this chef. In return, I learn; I benefit from their superior knowledge and skill. If I make a soup and the chef does not approve it, I don’t get offended and say, “You can’t reject my soup!”

Instead, I try to learn what I did wrong with the soup. I seek knowledge. I work on my skills. I try again. I make better soup.

In this situation, approval is the appropriate thing to pursue (for me) and the appropriate thing for the chef to give (or not).