Page History
The Total in DB Trending graph displays information measured in seconds about Internal Wait, Log Wait, Lock Wait, Tempdb I/O Wait, OS Wait, Using CPU, I/O Wait, Network I/O Wait, Remote Wait, and CLR Wait. All the Waits are color-coded and they are related to the Total in DB Highlights graph.
You can drill down the graph to choose into different time ranges and obtained more detailed information. intervals, click and drag the rectangle over the graph.