Paper/paper-api/src/main/java/org/bukkit/Axis.java

package org.bukkit;

/**
 * Represents a mutually perpendicular axis in 3D Cartesian coordinates. In
 * Minecraft the x, z axes lie in the horizontal plane, whilst the y axis points
 * upwards.
 */
public enum Axis {
    /**
     * The x axis.
     */
    X,
    /**
     * The y axis.
     */
    Y,
    /**
     * The z axis.
     */
    Z;
}