Although we already covered profiling in the previous chapter, the process we went through was like walking in the dark, or at least, in a place with very little light. We kept looking at numbers. Basically, we kept trying to decrease the number of hits, number of seconds, or other similar numbers. However, it was hard to understand how those numbers related to each other based on the representation we had of them.

We couldn't easily see the big blueprint of our system, based off of that output. If our systems would've been even bigger, seeing that blueprint would've been even harder.

Simply because we're human beings and not computers ourselves, we work better when we have some sort of visual aid. In this particular case, our work would benefit if we could better understand how everything is related. To do this, we have tools that provide visual representations of the numbers we saw in the previous chapter. These tools will...