---
title: "X"
subtitle: "Constant in std"
excerpt: "The X-axis (can be used in both 2d and 3d contexts)."
layout: manual
---

The X-axis (can be used in both 2d and 3d contexts).

```kcl
X: Axis3d
```



### Type

[`Axis3d`](/docs/kcl-std/types/std-types-Axis3d) - An abstract and infinite line in 3d space.