What is a key characteristic of caffeine?

Caffeine is a well-known stimulant that primarily affects the brain and nervous system. This key characteristic is significant as it highlights how caffeine can enhance alertness and reduce the perception of fatigue. The stimulation occurs because caffeine blocks the action of adenosine, a neurotransmitter that promotes sleepfulness, which leads to increased activity of neurotransmitters like dopamine and norepinephrine. As a result, individuals often experience feelings of increased energy and improved focus after consuming caffeine.

Understanding this characteristic is important for anyone involved in the coffee industry, as it enables baristas to explain the effects of different coffee varieties and prepare beverages that align with customer preferences and needs regarding energy and alertness.