A sophomore is a student in their second year of high school or college. In the United States, high school typically includes four grades: freshman, sophomore, junior, and senior. Sophomores are usually around 15 to 16 years old and are expected to build on the foundational knowledge they gained in their first year. During their sophomore year, students often take more advanced courses and begin to explore subjects that interest them for potential future studies. This year is crucial for academic development, as it helps students prepare for the challenges of their junior and senior years, including college applications and standardized tests.