A performance report consists of 5 tabs:
The task summary tab contains an overview of the task loading details for the specific occurrence of the task selected. There are tables with summaries of load times as well as Pie graphs to visualize these load times as a percentage of the whole load time.
The Performance tab displays the top 10% fastest loading elements as well as the 10% slowest loading elements, including the element size, download speed and time it took to download. This page is helpful in quickly identifying troublesome elements and speeding up the performance of your page.
The Waterfall Chart displays load times of each element in a bar chart in the order they were loaded along a timeline.
The hosts tab displays a waterfall chart broken down by the different hosts that are serving up content for this web page.
The errors tab lists any errors that the task received while attempting to load the content.