Caffeinated products are items that contain caffeine, a natural stimulant found in various plants. Common examples include coffee, tea, and energy drinks. Caffeine is known for its ability to increase alertness and reduce fatigue, making it popular among people looking for a quick energy boost. In addition to beverages, caffeine is also present in some foods and medications. For instance, chocolate contains small amounts of caffeine, while certain over-the-counter pain relievers may include it to enhance effectiveness. It's important to consume caffeinated products in moderation, as excessive intake can lead to side effects like insomnia and increased heart rate.