Before the implementation of GraphQl in Magento2.3 first, we should understand its basics. What is GraphQl?
GraphQl is a very powerful query language used to communicate data between client and server.GraphQL provides a complete and understandable description of the data in your API, gives clients the power to ask for exactly what they need, making it easier to evolve APIs over time, and enables powerful development tools and thus making GraphQl a more flexible & efficient approach than REST API.
Queries and Mutations in GraphQl
Queries
Queries are used by the clients to request the data they need from the server. GraphQL query performs the READ operation in a GraphQL API. Basically, it is similar to GET method in REST API.
Mutations
Mutations are used to perform the Create Update operation in GraphQl.It is similar to POST and PUT in REST API.
These are the basic approaches which we are going to use. If you want to learn more about GraphQl then you can visit this link (https://graphql.org/learn/)
We have explained Implementation of GraphQl in Magento2.3. We assume that you all know how to create the module in Magento 2, so we will not discuss it here. However, if you do not know then don’t worry, you can check Magento 2 Architecture https://cedcommerce.com/blog/magento-2-0-architecture/ to understand the basic magento 2 flow, and this link https://cedcommerce.com/blog/magento-2-0-architecture/ to understand the code structure of magento 2 and finally this link https://cedcommerce.com/blog/hello-world-module/ to know how to create a basic hello world module in magento2.