It often happens that we get questions from new users who don't understand the relationship between aperture, shutter speed, ISO, and lighting. And, it's often suggested that these questions are duplicates of What is the "exposure triangle"?.
However, as you can tell from my answer there, I'm really not a fan, and especially since that's the top answer, I don't think it's most helpful to send newbies off on that tangent. (I did try to start my answer by explaining the factors, so it's not a total wander down Pedantry Lane.)
I'd really love to see What is the relationship between ISO, aperture, and shutter speed? or a similar generic question like it reopened, and we can refer people to that instead, for a direct explanation without getting into Bryan Peterson's terminology.
Please join me in voting to reopen that question, or, if you have a better way to phrase what will hopefully be The Canonical Version of this basic question, edit it or even ask a new one.