The document defines the five major types of accounts: assets, liabilities, equity, income, and expenses. Assets are resources owned by a business. Liabilities are obligations of a business. Equity represents the owner's claim and is a residual interest calculated by deducting liabilities from assets. Income increases equity and expenses decrease equity. Current assets are expected to convert to cash within one year while non-current assets are long-term. Similarly, current liabilities are due within one year and non-current liabilities are long-term.