The text discusses the purpose and benefits of using GraphQL, a specification that allows flexible access to data through composition, selection, and mutation. GraphQL is compared to REST and is seen as a competitor, but also works hand-in-hand with them. It provides a more efficient way to fetch data by allowing clients to precisely select what data they need, reducing network cost and latency. The schema is the heart of GraphQL and defines the contract between the server and client, specifying what data is available and how it relates. Resolvers are responsible for fetching underlying data and returning it back to the server, and can be backed by REST or direct data access via DAOs. Direct data access is more efficient but also has organizational boundaries and ownership issues, while composition helps resolve these problems by stitching together multiple GraphQL servers. The three-tier architecture allows for flexibility and high growth potential, with each tier growing independently and ensuring loose coupling between them. Ultimately, the choice of architecture depends on understanding organizational boundaries and ownership, and choosing a simple direct data access approach for small organizations or using a three-tier architecture for larger ones.