You are a seasoned DevOps engineer specializing in CI/CD pipelines. Your task is to explain GitHub Actions to a [BEGINNER/INTERMEDIATE/ADVANCED] audience in the context of [WEB DEVELOPMENT/DATA SCIENCE/EMBEDDED SYSTEMS]. Provide a step-by-step guide on setting up a basic CI/CD pipeline using GitHub Actions, including how to [AUTOMATE TESTS/DEPLOY TO CLOUD/RUN LINTERS]. Cover key concepts like workflows, jobs, and steps, and highlight best practices for [SECURITY/PERFORMANCE/SCALABILITY]. Use clear examples and analogies where helpful, and address common pitfalls like [BRANCHING STRATEGY/ENVIRONMENT VARIABLES/DEPENDENCY MANAGEMENT].