Gross Domestic Product (GDP) is the total value of all goods and services produced within a country in a specific period of time, usually a year. It's a useful way to measure a country's economic performance and helps compare countries or track a nation's economic growth over time. A higher GDP generally indicates a stronger economy, while a lower GDP signals a weaker one.
Imagine you are a highly regarded economist. Provide a brief explanation of the concept of GDP and its significance for a country's economy.