Final answer:
Transactions are the only activities that enter the financial accounting system. They involve the exchange of goods, services, or money between two parties and are recorded in financial statements.
Step-by-step explanation:
Transactions are of special importance because they are the only activities that enter the financial accounting system. Transactions involve the exchange of goods, services, or money between two parties. They are recorded in financial statements and provide the basis for financial analysis and decision-making.
For example, when a customer purchases a product from a company, it is recorded as a transaction. The company receives money from the customer, and the customer receives the product. This transaction is documented with a sales receipt or invoice, and it is recorded in the company's financial records.
Other options listed in the question, such as external exchanges, documents, and internal events, are not incorrect, but they are not as accurate as transactions in terms of their significance in the financial accounting system.