What does a 'Frame' represent in the context of the Web Profile?

In the context of the Web Profile, a "Frame" specifically represents a single invocation of a profiled section of code. This means that a frame is defined by the execution of a specific code section that can be analyzed for performance and behavior. Each time that section of code is executed, it corresponds to one frame of profiling information.

This granularity allows developers and performance analysts to closely monitor and measure the performance of individual code sections, which can provide insights into which specific parts of the application may need optimization. By examining frames, it is possible to identify bottlenecks or inefficiencies that could affect the overall user experience.

In contrast, other choices describe different concepts. The notion of a server round trip relates more to interactions between the client and the server, which may encompass multiple frames, while user sessions aggregate all frames over a longer duration. Summary reports are collected after profiling is complete and provide a higher-level view of multiple frames rather than focusing on the detail of a single code invocation. Thus, option B, as the correct answer, best captures the specific essence of what a "Frame" indicates in this profiling context.