Need help to understand code!

I found this code and when i run it, the code creates particles in a 1024 by 1024 by 128 radius (Like minecraft but particles). I tried anylizing this it, but when i got about half way through i got stuck. I tried looking it up but didn;t fined anything that has a good explination of how it works. Could someone please explain what the code means that i’m confused on. If you could brake it down into what each part does would be awesome. thanks.
Code: `

using UnityEngine;

public class NoiseTest : MonoBehaviour{

private ParticleEmitter m_ParticleEmitter;
// Use this for initialization
private void Start()
{
    m_ParticleEmitter = gameObject.GetComponent<ParticleEmitter>();
}

private bool m_FirstTime = true;
// Update is called once per frame
private void Update()
{
    Debug.Log(m_ParticleEmitter.particleCount); //number of particles in the current particel

    int count = 0;
    Particle[] particles = m_ParticleEmitter.particles;
    
	for (int x = 0; x < 1024; x++)
    {
        for (int z = 0; z < 1024; z++)
        {
            for (int y = 0; y < 128; y++)
            {
                float groundHeight = PerlinSimplexNoise.noise(x*0.001f, z*0.001f, y*0.001f)*64.0f;
                groundHeight += PerlinSimplexNoise.noise(x*0.01f, z*0.01f, y*0.01f)*32.0f;
                groundHeight += PerlinSimplexNoise.noise(x*0.1f, z*0.1f, y*0.1f)*4.0f;
                //groundHeight = Mathf.Clamp(groundHeight, 0, 127);

                particles[count].position = new Vector3(x + y, groundHeight, z);
                if (count < particles.Length -1)
                {
                    count++;
                }
                else
                {
                    UpdateDisplay(particles);
                    return;
                }
            }
        }
    }
}

private void UpdateDisplay(Particle[] particles)
{
    m_ParticleEmitter.particles = particles;
}

}`

this code is simply updating some particles position (y) until the particles array is full or it has updated all of them

then it returns from the Update function

it’s using a perlin noise to move each particle height position…

not that hard to read…

anyway hope that helps…