This diagram was created by Dr. Bill McCallum (one of the three lead architects of the math standards) to explain the Structure of the 8 Mathematical Practices. The 8 Mathematical Practices are defined on pages 5-7 of the Common Core Standards for Mathematics. They are also listed at the beginning of each grade level's standards.
Dr. McCallum noted, "if you try to do everything all the time, you end up doing nothing." Rather than saying we are doing every practice every day, it makes sense to find places in our instruction where we can focus on developing a specific practice. These skills are not innate. Students will need instruction and feedback to help them develop their ability to put these practices into action.
So what do we want to gain through these practices? These practices are the foundation for a paradigm shift in mathematics. We want students who are equipped to be mathematical thinkers vs. students who expect the teacher to do all the thinking for them. Students who don't panic if the answer isn't obvious when they first glance at a problem. Students who have the tools to make sense of a problem, the stamina to persevere, and the skill to communicate their thinking with precision.
Phil Daro (one of the three lead architects of the math standards) explains how the standards can help us move away from "Answer Getting Techniques" (middle tab) that obscure the mathematics we want students to learn.