【中文版】

市场经济是指通过市场配置社会资源的经济形式。简单来说，市场就是商品或劳务交换的场所或接触点。市场可以是有形的，也可以是无形的。在市场上从事各种交易活动的当事人，称为市场主体。

市场主体包括消费者、生产者、中间商和政府等。在市场上，资源通过各种市场机制自发地流向最需要的地方，从而实现资源的优化配置。市场经济能够提高社会资源的利用效率，促进经济的快速发展，同时还能满足人们多样化的需求。

市场经济也存在一些问题和挑战。市场失灵、市场垄断、外部效应等问题会影响市场的正常运转。此外，市场经济的自由放任也会导致收入差距扩大、环境污染等问题。因此，政府需要加强对市场的监管和调控，以保障市场的健康发展和社会的公平正义。

总的来说，市场经济是一种高效、灵活的经济形式，能够促进经济的发展和社会的进步。然而，市场经济的正常运转也需要政府的有力监管和调控，以避免市场失灵和市场垄断等问题。

【英文版】

Market economy refers to an economic system in which social resources are allocated through the market. In short, the market is the place or contact point for the exchange of goods or services. The market can be tangible or intangible. The parties involved in various transactions in the market are called market entities.

Market entities include consumers, producers, intermediaries, and government. In the market, resources flow spontaneously to where they are most needed through various market mechanisms, thus realizing the optimal allocation of resources. Market economy can improve the utilization efficiency of social resources, promote rapid economic development, and also meet people's diverse needs.

However, there are also some problems and challenges in the market economy. Market failure, market monopoly, external effects and other issues can affect the normal operation of the market. In addition, the laissez-faire of the market economy can also lead to income差距扩大, environmental pollution and other issues. Therefore, the government needs to strengthen supervision and regulation of the market to ensure the healthy development of the market and social justice.

Overall, the market economy is an efficient and flexible economic system that can promote economic development and social progress. However, the normal operation of the market economy also requires strong government supervision and regulation to avoid problems such as market failure and market monopoly.