中文：

人口红利是指一国或一地区在特定时间内劳动年龄人口数与非劳动年龄人口数的比值较高，从而产生的一个经济现象。在人口红利的阶段，劳动力资源相对丰富，为经济发展提供了有利条件。

人口红利的产生主要源于生育率的下降和寿命的延长。随着社会经济的发展和生育观念的改变，生育率逐渐下降，同时人们的生活水平和医疗水平的提高也延长了寿命，导致劳动年龄人口数量相对较多，而非劳动年龄人口数量相对较少。

人口红利对于经济发展的影响主要表现在以下几个方面：一是劳动力资源丰富，为企业提供了更多的选择余地，降低了生产成本；二是劳动力市场相对宽松，就业机会增多，为经济发展提供了稳定的社会环境；三是消费结构逐渐升级，为经济发展提供了新的动力。

然而，人口红利并不是永恒的，随着人口结构的变化，劳动力资源逐渐减少，人口红利逐渐消失。因此，要保持经济的持续发展，需要转变发展方式，提高劳动力素质，推动产业升级和技术创新。

英文：

Demographic dividend refers to an economic phenomenon in which a country or region has a high ratio of working-age population to non-working-age population during a specific period of time. During the demographic dividend phase, the relative abundance of labor resources provides favorable conditions for economic development.

The demographic dividend mainly stems from the decline in fertility rates and the extension of lifespan. With the development of social economy and changes in fertility concepts, fertility rates gradually decline, while the improvement of people's living standards and medical conditions also extend lifespan, resulting in a relatively large number of working-age population and a relatively small number of non-working-age population.

The impact of demographic dividend on economic development mainly manifests in the following aspects: first, the abundant labor resources provide more choices for enterprises, reducing production costs; second, the relatively loose labor market and increased job opportunities provide a stable social environment for economic development; third, the gradual upgrading of consumption structure provides new impetus for economic development.

However, demographic dividend is not eternal. With the change of population structure, labor resources gradually decrease, and demographic dividends gradually disappear. Therefore, to maintain sustained economic development, it is necessary to transform development methods, improve labor quality, and promote industrial upgrading and technological innovation.