Article 153 is like a special rule in Malaysia's big rule book (the Constitution) that says that the government can help out certain people who might need extra help because of their race or religion.
It's like if the teacher in a class noticed that some of the kids were having a hard time understanding the math, so she decided to help them a little more. In Malaysia, the government can do things like make sure that people from certain races or religions have fair opportunities for things like jobs, education, and housing.
This rule has been around for a long time, since Malaysia became independent in the 1950s. The idea behind it is to help make sure that everyone in Malaysia has a fair chance to succeed, even if they come from different backgrounds. It's kind of like the teacher making sure that everyone in the class has a chance to do well, no matter what their strengths and weaknesses might be.