What are the differences between local, dev, stage, and prod environments?

The local, dev, stage, and prod environments are used to separate the stages of development and operation of the application:

• local — the developer's local environment. The application runs here on the developer's machine with minimal configuration, often with mocks or simplified services.
• dev (development) — an environment for integration and testing of new features by the team. Usually, this is a shared server where the latest changes are collected.
• stage (staging) — an intermediate environment, as close as possible to production. Final testing, performance, and security checks are performed here before release.
• prod (production) — the live environment where the application is available to end users.

Each environment differs in configuration, access levels, used services, and data. This helps minimize risks and ensure stability in production.