GraphQL, open-sourced by Facebook in 2015, is a query language designed to improve client-server communication and is widely adopted by companies like PayPal, Shopify, and GitHub as an alternative to REST. It features a strongly typed schema that acts as a contract between client and server, facilitating easier interaction, early error detection, and independent work for frontend and backend teams. GraphQL supports primitive scalar types such as Int, Float, String, Boolean, and ID, and allows for complex object definitions and enum types to validate arguments. The language includes query and mutation types for data retrieval and modification, resembling GET and POST requests in REST, and offers flexibility with non-nullable fields and list combinations. GraphQL's robust schema capabilities help reduce miscommunication and streamline the development cycle, although challenges remain in monitoring its performance in production, where tools like LogRocket can assist in debugging and ensuring reliable data delivery.