【中文版】

经济学是研究人类社会在各个发展阶段上的各种经济活动和各种相应的经济关系及其运行、发展的规律的科学。经济学核心思想是物质稀缺性和有效利用资源，可分为两大主要分支，微观经济学和宏观经济学。

微观经济学，又称为个体经济学，是现代经济学的一个分支，主要研究经济体系中最基本单元的经济学。其着眼点是单个经济单位，即企业和家庭。微观经济学与宏观经济学的区别在于它们的经济变量不同。两者之间的呼应使得它们成为现代西方经济学的基本构成部分。

宏观经济学，又称为总体经济学、体系经济学，开放型宏观经济学，是现代经济学的一个分支，研究的对象是整个国民经济。在开放经济条件下，整个宏微观经济学的结构体系基本相同，只是重点转向了国民收入的决定。

总的来说，经济学是一门研究人类社会经济现象和规律的科学，对于人类社会的发展有着重要的贡献。

【英文版】

Economics is the science that studies the economic activities and their corresponding economic relationships in various stages of human society, as well as the laws of their operation and development. The core idea of economics is the scarcity of materials and the effective utilization of resources. It can be divided into two major branches: Microeconomics and Macroeconomics.

Microeconomics, also known as individual economics, is a branch of modern economics that mainly studies the economic units in the smallest units of the economy, such as individual businesses and households. The difference between Microeconomics and Macroeconomics lies in their economic variables. The complementarity between the two makes them the basic components of modern Western Economics.

Macroeconomics, also known as aggregate economics, open macroeconomics, is a branch of modern economics that studies the entire national economy. In an open economy, the structure and system of Microeconomics and Macroeconomics are basically the same, but the focus is shifted to the determination of national income.

Overall, Economics is a science that studies economic phenomena and laws in human society, making important contributions to the development of human society.