D3 was initially released without the built-in support of the Axis component. This situation did not last long; since axes are the universal building blocks in many Cartesian coordinate system-based visualization projects, it quickly became clear that D3 needs to provide built-in support for axes. Therefore, it was introduced quite early on and is continuously being enhanced ever since it was released. In this chapter, we will explore the usage of the Axis component and some related techniques.