In reply to Nirmal Kumar.

Hey!

WPGraphQL allows developers the ability to declaratively and efficently interact with WordPress data using the GraphQL query language.

There are many benefits to using GraphQL, but a big one is performance. Requesting data from GraphQL allows the consumer to specify the fields needed, which allows the WordPress server to do the minimum processing needed to get the data returned to the consumer. Where in other APIs, such as REST, the server sends an entire payload of data and does all the relational queries to get connected term IDs, etc even if the consumer is only interested in the title, for example.

There are also many features of the GraphQL Query Language, such as aliasing and query fragments that make component-based development (React, Vue, etc) much easier to manage, as the data dependencies can be handled by the component, and not be some arbitrary data layer of the client application.