The Apollo Tracing extension for GraphQL servers enables performance monitoring by including trace data in the `extensions` field of the response. This allows developers to visualize and analyze the performance of their resolvers, similar to how error paths are handled in the GraphQL spec. The tracing format is designed to be flexible and include detailed timings and type information for individual resolvers. With support built-in for Apollo Server, users can easily enable tracing by setting `tracing` to `true`. The extension already works with popular server libraries such as Node, Ruby, Scala, Java, and Elixir, and the community is encouraged to contribute support for other servers and tools.