Caffeine

Each day, billions of people rely on caffeine to wake up, or to get through that night shift or an afternoon slump. In fact, this natural, plant based stimulant is one of the most commonly used ingredients in the world. Caffeine is often talked about for its negative effects on sleep and anxiety. However, studies also report that it has various health benefits.

Caffeine stimulates the brain and promotes a state of arousal, alertness, and focus. Because it affects your brain, caffeine is often referred to as a psychoactive drug. Additionally, caffeine tends to exert its effects quickly.

https://www.healthline.com/nutrition/what-is-caffeine#what-it-is

Hydrology

Hydrology is the science that encompasses the occurrence, distribution, movement and properties of the waters of the earth and their relationship with the environment within each phase of the hydrologic cycle. The water cycle, or hydrologic cycle, is a continuous process by which water is purified by evaporation and transported from the earth's surface (including the oceans) to the atmosphere and back to the land and oceans. All of the physical, chemical and biological processes involving water as it travels its various paths in the atmosphere, over and beneath the earth's surface and through growing plants, are of interest to those who study the hydrologic cycle.

https://www.usgs.gov/special-topic/water-science-school/science/what-hydrology?qt-science_center_objects=0#qt-science_center_objects