The phrase "upper chest" refers to the area of your body above your stomach and below your neck. It includes your collarbone, upper ribs, and the muscles in that region. Full definition
That being said, training experts and bodybuilders alike agree that it's essential to combine both exercises in your chest training program in order to ensure balanced and complete upper chest muscle growth. (fitnessandpower.com)
Not saying you can't do it, but I'd like to focus more on upper chest. (fitmole.org)
The bar should finish at the in front of your lower neck / upper chest region. (mystrengthtraining.com)