Before we learn what GraphQL is, we need to know what an API is and how it works?
Application Programming Interface or simply an API is a software programming consisting of a set of definitions and protocols that allow two computer programs to interact with each other in an orderly fashion to present data as requested by users. The interaction of the mobile app with the server is completed through the use of API.
Now GraphQL is a query language for APIs & runtime. It helps to fulfill the requested queries with existing data. To simply put it, it helps to speed things up by boosting the interaction between APIs. It helps to enhance the flexibility and effectiveness of the call or query requested.
GraphQL is a high-performing alternative for REST & SOAP APIs. It helps to build custom headless storefronts, PWA apps, and mobile apps in Magento. REST, SOAP, and GraphQL have similar functionalities. However, REST and SOAP have less advanced architecture than its counterpart.
GraphQL was introduced with Magento 2.3 and Magento plans to complete its coverage with the Magento 2.4.X. Even though advanced capabilities, it has some disadvantages as well. Read more to find out. Read Full Blog here: Magento 2 GraphQL: Detailed Guide on Capabilities and Uses