i mean scientifically (source is my brain) it temporarily boosts activity in the brain, it also acts as a block for the neurotransmitter that makes u sleepy sleepy gngn time causing u to become more alert. It also increases concentration i think but idk how.
it does help for a short bit if you firstly drink caffeine. but later if you've built up tolerance then its pretty much the same as if you've not drank anything
caffeine helps in my performance although i need to drink 2 or more cups of coffee just to feel its effect again but sometimes just one cup is enough
For me it certainly can. Caffeine is a stimulant, it makes you feel like you have more energy and focus, but aside from that mental boost, it doesn't help you physically.