Imagine you have a toy box with many toys in it, and you cannot take all the toys with you everywhere. You have to choose only some of your favorite toys to take with you.
In the same way, countries have limits on how many people can come and live with them. For example, a country may only allow 100,000 people to come and live there in one year, but there might be more than a million people who want to come and live there.
To decide who to let in, countries use a Points-based immigration system. A point-based immigration system is like a game where you score points based on certain things, just like you earn points for playing games or completing tasks.
In a points-based immigration system, people who want to move to a country need to earn certain points based on the skills, education, language proficiency, age, and other factors that the country may be looking for.
For example, if the country needs a lot of nurses or engineers, it may give extra points to people who have those skills. If the country wants people who are fluent in its language, it may give extra points to people who speak that language well.
Similarly, if the country wants young and healthy people to move in, it may give fewer points to older people or people with health problems.
Once a person earns enough points, they might be selected to move to the country. It all depends on how many points they have earned, and how many people the country can allow.
Just like you choose your favorite toys to take with you, the country chooses the people with the most points to come and live with them.