Steam is a gas that forms when water is heated to its boiling point. When water reaches 100 degrees Celsius (212 degrees Fahrenheit), it transforms from a liquid into vapor, creating steam. This process is essential in many everyday activities, such as cooking and powering engines. For example, steam engines use steam to create movement, revolutionizing transportation in the 19th century. In addition to its practical uses, steam plays a role in nature. When the sun heats water in rivers and lakes, it evaporates and rises into the atmosphere as steam. This process is part of the water cycle, which helps maintain the balance of our environment by distributing moisture and supporting plant growth.