Vanguardism is a big and complicated word that means when a group of people want to make a big change in their society, they create a smaller group of people who are very committed to making that change happen. These people are called the "vanguard," and they usually have a very clear idea of what they want to change in their society and how to change it.
Think of it like this: imagine you and your friends want to build a big sandcastle on the beach. But building a sandcastle is not easy and requires a lot of work, so you decide to pick a few friends who are really good at making sandcastles to help you. These friends become the vanguard of your sandcastle-building team. They know exactly what kind of sand to use, how to shape the castle, and how to make it look beautiful.
Similarly, when a group of people wants to change their society, they may create a vanguard of people who are very committed to making that change happen. These people may have a lot of knowledge about the issue, experience in organizing others, and a clear plan of action to achieve their goal.
However, it's important to note that vanguardism can be controversial. Some people argue that it can lead to a small group of people having too much power and ignoring the needs and opinions of others. Others argue that vanguardism is necessary for making real and lasting change in society.