A decade is a period of ten years. It is commonly used to measure time in various contexts, such as history, culture, and economics. For example, the 1980s is often referred to as a decade known for its distinctive music, fashion, and technological advancements. Each decade can have its own unique characteristics and events that shape society. Decades are often grouped into larger time frames, such as centuries or millennia. People may refer to decades by their starting year, like the 2000s or the 2010s. This helps in organizing historical events and trends, making it easier to understand changes over time.