GraphQL APIs, originally developed by Facebook in 2012, are designed to handle queries, mutations, and subscriptions using HTTP requests, enabling precise data retrieval without under-fetching or over-fetching. Unlike REST APIs, which focus on accessing data collections, GraphQL emphasizes the relationships between data elements, allowing queries to traverse through these relationships to deliver only requested data. GraphQL APIs are built on schemas, which validate operations before execution, and support CRUD operations independent of HTTP methods, often using JSON for responses. They are widely implemented in various programming languages and are favored for their efficiency in handling diverse data requests and integrating disparate data sources through federation. Despite being relatively young, their popularity is growing rapidly, as shown by increasing adoption rates, and they offer developers flexibility and simplicity by allowing them to query the server directly for available queries and mutations.