An "era" is a significant period in history characterized by particular events, developments, or cultural trends. Eras can be defined by various factors, such as political changes, technological advancements, or social movements. For example, the Industrial Revolution marked a shift from agrarian societies to industrialized ones, leading to profound changes in daily life. Eras are often used to categorize historical timelines, making it easier to study and understand the past. Each era can have distinct features, such as the Renaissance, known for its advancements in art and science, or the Digital Age, defined by the rise of technology and the internet.