【中文版】

CPI即消费者物价指数，是反映与居民生活有关的商品及劳务价格统计出来的物价变动指标，通常作为观察通货膨胀水平的重要指标。

CPI的计算公式是：CPI=（一组固定商品按当期价格计算的价值/一组固定商品按基期价格计算的价值）×100%。简单来说，CPI就是用来反映居民购买的商品和劳务的价格变动情况。

CPI是一个非常重要的经济指标，它反映了居民的购买力和消费水平，也反映了经济的通货膨胀水平。如果CPI上升，意味着居民购买商品和劳务的价格上涨，通货膨胀的压力也在增加。因此，政府和社会各界都会关注CPI的变化，以便采取相应的措施。

然而，CPI也存在一些问题和局限性。首先，由于CPI是一组固定商品和劳务的加权平均价格，因此它不能完全反映居民的购买力和消费水平。其次，由于不同商品和劳务的价格变动不同，CPI也可能存在偏差。最后，由于CPI是一个月公布一次，因此它也不能及时反映经济的通货膨胀情况。

总之，CPI是一个重要的经济指标，它反映了居民的购买力和消费水平，也反映了经济的通货膨胀水平。政府和社会各界都会关注CPI的变化，以便采取相应的措施。同时，我们也需要了解CPI存在的问题和局限性。

【英文版】

CPI, which stands for Consumer Price Index, is a price index for goods and services related to household consumption, usually used as an important indicator to observe the level of inflation.

The calculation formula of CPI is: CPI = (the value of a fixed set of goods at the current price/the value of a fixed set of goods at the base price) × 100%. In simple terms, CPI reflects the price changes of goods and services purchased by residents.

CPI is a very important economic indicator, reflecting the purchasing power and consumption level of residents, as well as the inflation level of the economy. If CPI rises, it means that the price of goods and services purchased by residents is rising, and the inflationary pressure is also increasing. Therefore, the government and all sectors of society will pay attention to the changes of CPI, so as to take corresponding measures.

However, CPI also has some problems and limitations. Firstly, CPI is the weighted average price of a fixed set of goods and services, so it cannot fully reflect the purchasing power and consumption level of residents. Secondly, due to the different price changes of different goods and services, CPI may also be biased. Finally, CPI is announced once a month, so it cannot reflect the inflation situation of the economy in a timely manner.

In summary, CPI is an important economic indicator that reflects the purchasing power and consumption level of residents, as well as the inflation level of the economy. The government and all sectors of society will pay attention to the changes of CPI, so as to take corresponding measures. At the same time, we also need to understand the problems and limitations of CPI.