Revenue is a fundamental financial metric for any business, representing the total earnings derived from selling goods or services to customers before any expenses or costs are deducted. It serves as the primary indicator of a company's sales performance and its ability to generate income through its core business operations. Revenue is crucial for financial analysis as it serves as a starting point for calculating various other key indicators, such as profit margins and growth rates.

There are various ways of categorizing revenue, such as product sales revenue or service revenue. For example, when a retailer sells a $50 item to a customer, the $50 earned is recorded as revenue. Similarly, a service provider charging $100 for advisory services would recognize $100 as revenue. For most businesses, consistent revenue trends indicate operational stability and market acceptance of their offerings.

Revenue is recognized when it is earned and realizable, in line with accounting standards such as Generally Accepted Accounting Principles (GAAP). Analyzing a company's revenue can provide insights into its market position, strategic growth initiatives, and overall business health.