How does GraphQL differ from REST in querying data, and what are the benefits and potential drawbacks of using GraphQL in a web application?

GraphQL allows clients to request exactly the data they need, reducing over-fetching and under-fetching issues common in REST APIs. It provides a flexible and efficient way to query nested and related data. Benefits include improved performance and developer experience. However, drawbacks include increased complexity in implementation, potential performance issues with poorly designed queries, and the need for proper authorization and validation mechanisms.