Add section od querying data (#25182)

* Add section od querying data

* fix: corrected spacing in sentences

guide/english/gatsbyjs/index.md

@@ -32,5 +32,10 @@ Gatsby deploys the site on a static web host such as Amazon S3, Netlify, Github
 * To generate the static HTML pages use `gatsby build`
 * `gatsby serve` will start a local server that will present your built site.
 
-### More Information:
+### Querying data
+
+You are accessing all data by writing GraphQL queries. GraphQL allows you to pull only the data you need into your components, unlike when fetching data from REST API. A detailed walktrough is available at https://www.gatsbyjs.org/tutorial/part-four/?no-cache=1#how-gatsbys-data-layer-uses-graphql-to-pull-data-into-components.
+
+#### More Information:
+
 For tutorials and more information check out the Gatsby.js official site: [Gatsby.js official site](https://www.gatsbyjs.org/tutorial/)