A feature file (.feature) is a plain-text file containing one Feature and its scenarios written in Gherkin. It is the executable specification and the entry point Cucumber reads.
Feature files live in a resources/features folder (by convention) and describe one capability per file (Login.feature, Checkout.feature). A file begins with an optional narrative (As a... I want... So that...) under Feature:, followed by scenarios. Keeping features focused and named by capability aids organization and discoverability. Feature files are version-controlled alongside code so the specification evolves with the product. The narrative and scenario titles serve as documentation; well-organized feature files let stakeholders find and read behavior without touching code.
Checkout.feature groups all checkout scenarios (empty cart, discount applied, payment failure) under one Feature with a narrative, so anyone can read the checkout behavior in one place.
How should you organize scenarios across feature files, and why not put everything in one big file?