WordPress and React can be combined to create a powerful web application. WordPress provides an easy-to-use content management system, while React provides a modern JavaScript framework for building user interfaces. Gatsby is used as a static site generator to compile React code and data into static assets. GraphQL allows developers to query data from the WordPress site in a flexible and efficient way. By combining these technologies, developers can create fast-loading web applications with a rich set of features and plugins. The tutorial provides step-by-step instructions on how to use WordPress with React, including setting up local hosting, creating a GraphQL API, pulling data into Gatsby, and adding styling to the application.