Rental real estate investing involves purchasing property (residential or commercial) and leasing it to tenants to generate monthly income. Investors use leverage (mortgages) to control properties worth 5–10x their cash down payment, amplifying returns. Success depends on location selection, tenant quality, expense management, and long-term hold discipline. The business model is simple: rent > expenses = profit. But execution is complex: finding deals, underwriting, financing, tenant management, maintenance, tax optimization, and market cycles.