@actions/core is a fundamental package for GitHub Actions development. It provides a simple and consistent interface for core functions like setting output variables, reading input parameters, masking secrets, logging messages with different severity levels (info, warning, error), and managing action state. This package streamlines the creation of robust and reusable GitHub Actions by abstracting away the complexities of the underlying runner environment. Developers can use it to build, test, and deploy code automation workflows with ease.