Okay kiddo, have you ever played with Legos and built a big house or a castle? Imagine that you have a bunch of tiny Legos that you want to use to build a big toy castle. You start by putting the Legos together one by one, making a small square of four Legos. Then, you connect another square to that one and keep building until you have a big castle.
Now imagine if you were a scientist exploring the really small world of particles. You might study something called a quark, which is one of the tiny building blocks of matter. Quarks come in six different types, and they can combine in lots of different ways to make bigger particles called hadrons.
Hadronization is like building a big toy castle out of Legos, but instead of Legos, scientists are using quarks (and sometimes another particle called a gluon). When two very high-energy particles smash into each other, some of their quarks might get knocked loose. These loose quarks can then combine with other quarks to form new particles, like protons and neutrons, which are types of hadrons.
So, hadronization is the process of building bigger particles out of smaller building blocks (quarks). Just like Legos can be used to build all kinds of things, quarks can be combined in different ways to create different types of particles. Scientists study hadronization so they can better understand how the universe works at the tiniest level.