Coffee is one of the most popular beverages in the world, and its popularity is due to its effective impact on alertness and concentration. Coffee contains caffeine, which stimulates the brain and enhances its functions, making it a preferred choice for many people before work or study. Impact on the Brain Caffeine blocks adenosine receptors in the brain, which are responsible for the feeling of fatigue. The result is a greater sense of alertness and improvement in response speed and decision-making. Studies have also shown enhancements in short-term memory and mental performance after drinking a cup of coffee. Health Benefits of Coffee Coffee helps improve mood and reduce depression, and it also contributes to increasing metabolism and fat burning when consumed in moderation. Some studies have indicated that drinking coffee in moderate amounts may reduce the risk of diseases such as Alzheimer’s and Parkinson’s. Potential Risks of Excessive Coffee Intake Excessive consumption of coffee may cause anxiety, insomnia, and heart palpitations. Some individuals are more sensitive to caffeine, which may lead to digestive disturbances or headaches. Therefore, adults are advised not to exceed 3–4 cups per day. Conclusion Coffee is an enjoyable and beneficial beverage when consumed in moderation, as it enhances alertness, concentration, and mental performance. By understanding its effects on the brain, one can benefit from it safely and effectively in daily life. Al-Mustaqbal University — the No. 1 university in Iraq.