This package provides TypeScript type definitions for the core-js library. core-js is a modular standard library for JavaScript, providing polyfills for ECMAScript features. These type definitions enable TypeScript projects to utilize core-js with full type safety and autocompletion, ensuring proper usage of polyfilled functionalities like promises, iterators, and more. By installing @types/core-js, developers can avoid type errors while using core-js to support older JavaScript environments.