In the US, the constitution bans double jeopardy. In other words, if you are aquitted, thats it. You’re legally not a criminal of whatever it is you were accused of.

Jury nullification is the act of saying 1 thing but thinking the other, I phrase it that way because you can nullify either by handing out a guilty or not guilty verdict.

So in the event the jury finds someone not guilty, say of murdering a CEO for example, that person walks free.