GraphQL is an API query language that allows developers to fetch and manipulate data from a backend system through a standard HTTP request, providing a flexible and efficient way to communicate between frontend and backend applications. It was developed by Facebook in 2012 and made open source in 2015, making it a powerful tool for building robust and scalable applications. With its language-agnostic design, GraphQL can be used with any framework or programming language, allowing developers to query data from multiple resources in one API call, reducing the need for separate requests and improving efficiency. The query syntax is designed to feel familiar and natural, with objects and relationships represented as a graph structure that can be queried and represented in a user interface. GraphQL also provides introspection queries to generate documentation and provide hints in the GraphQL UI, making it easier for developers to understand and use the API. Additionally, GraphQL allows for mutation of data via the mutation keyword, enabling developers to change or manipulate server-side data. With its wide range of libraries and platforms available, GraphQL is a popular choice for building efficient and scalable applications.