In a speech at the UN General Assembly on September 22, 2020, President Xi Jinping announced that China would peak carbon dioxide emissions before 2030 and achieve carbon neutrality before 2060. China has issued a series of documents on the carbon peaking and neutrality goals, which have become hot issues in society. The concept of carbon peaking is relatively easy to understand, but for that of carbon neutrality, there are some misunderstandings, such as mixed use of different terms and ambiguous scope, classification, and relationships between related concepts, which not only directly affect the implementation of the 'dual carbon' goals in China, but also impede Chinas participation in global climate governance and international climate cooperation towards the goal of carbon neutrality. This paper attempts to trace the origin and evolution of the concept of carbon neutrality. It sorts out the different expressions of the carbon neutrality goal, compares the differences and correlations between related concepts, and discusses the key elements and implications of the concept of carbon neutrality. The discussion leads to the following conclusions: ① The concept of carbon neutrality was introduced to the field of global climate governance after carbon trading and carbon offsetting had been proposed in the Kyoto Protocol in 1997. ② The concept of carbon neutrality has both narrow and broad senses. Narrowly speaking, it refers to carbon dioxide neutrality, while in a broad sense, it is a collective term for related concepts such as carbon dioxide neutrality, greenhouse gas neutrality, climate neutrality, net zero carbon dioxide emissions, and net zero greenhouse gas emissions. In the international community, the expression 'net zero' is more widely used. ③ To understand the concept of carbon neutrality, four elements need to be grasped: the balance between the source and removal of anthropogenic emissions; multiple implementation entities and their carbon accounting boundaries; the scope of emissions (covering merely carbon dioxide or all greenhouse gases); and carbon neutralization paths including carbon emission reduction, carbon removal, carbon offsets, etc. ④ Clarifying the concept of carbon neutrality is the basis for efficiently implementing the 'dual carbon' goals and promoting international cooperation. The terms used in the legal documents and IPCC guidelines and reports approved in the UNFCCC negotiations are internationally accepted concepts and norms. They are recognized by various governments and serve as an important foundation for scientific research as well as the cognitive basis for international negotiations and actions. The definition and interpretation of the concept of carbon neutrality should be consistent with the international community as much as possible to form a unified understanding that is not only conducive to promoting international cooperation towards carbon neutrality, but also to China' s implementation of the Paris Agreement and advancement of work towards the 'dual carbon' goals. [ABSTRACT FROM AUTHOR]