Yes, we can call the profit and loss account of a firm as an income statement.

Definition of Income Statement:
The income statement is a financial statement that summarizes the revenues, expenses, and resulting profit or loss of a company during a specific period of time. It provides a comprehensive overview of a company's financial performance over a given period, typically a fiscal quarter or year. The income statement is one of the key financial statements used by investors, creditors, and analysts to assess the financial health and profitability of a company.

Relationship between Profit and Loss Account and Income Statement:
- The profit and loss account is a statement prepared by a business to summarize its revenues, expenses, and resulting profit or loss over a specific accounting period.
- The income statement is a financial statement that serves the same purpose, i.e., to summarize a company's revenues, expenses, and profit or loss over a specific period.

Key Points:
1. Both the profit and loss account and the income statement aim to provide a comprehensive picture of a company's financial performance.
2. They summarize the company's revenues, expenses, and profit or loss over a specific period.
3. The terms "profit and loss account" and "income statement" are often used interchangeably in practice.
4. The choice of terminology may vary depending on the country and accounting standards followed.
5. For example, in the United States, the term "income statement" is more commonly used, while in some other countries, "profit and loss account" is the preferred term.
6. Regardless of the terminology used, the purpose and content of the statement remain the same.

Conclusion:
In conclusion, the profit and loss account of a firm can be referred to as an income statement. Both terms represent the same financial statement that summarizes a company's revenues, expenses, and profit or loss over a specific period. The choice of terminology may vary, but the purpose and content of the statement remain consistent.