3.1. This chapter deals with the basic nature of the entries in the accounts and tables of the System. First, it defines the nature of flows and stocks. These are the two basic forms in which information about the economy can be recorded in a system of national accounts, flows referring to actions and effects of events that take place within a period of time and stocks referring to a position at a point of time. Secondly, it explains the rules of accounting that underlie the recording of flows and stocks. The discussion in this chapter is a general one; definitions of specific flows and stocks and specific applications of the accounting rules appear in later chapters.