Assets are objects or entities that have economic value for a company, including tangible assets like equipment and buildings, as well as intangible assets like patents and accounts receivable. Assets are classified as current, fixed, or long-term depending on their liquidity and lifespan. Liabilities are financial obligations like loans that a company owes, classified as current or long-term. Equity or capital represents the owner's financial stake in the company and is calculated by subtracting liabilities from total assets. Income is revenue earned from sales or interest, while expenses are costs that allow a company to operate.