Kleshas are like bad monsters that live inside our minds and cause us to feel unhappy, anxious or angry. You know how sometimes you feel angry even when someone says something small, or sometimes you worry too much about things that haven’t even happened yet? Those are examples of kleshas.
There are five different types of kleshas that Buddhists talk about. One is called ignorance, which means not understanding things clearly. This can make you worry too much, feel scared, or make decisions that aren't very good. Another one is attachment which means really, really liking things and not wanting them to change. This can make you feel really upset when something changes or you can't have something you want.
Then there’s aversion, which means really not liking something and wanting it to go away. This can make you feel angry, hateful or even mean to others. Then there's pride, which is when you think you're better than everyone else and don't listen to their ideas or feelings. And finally, delusion, which is when you get confused about what's real and what isn't.
Buddhists try to get rid of these kleshas by meditating and being kind and compassionate to others. They believe that by doing this, they can control their thoughts and feelings better and be happier in their lives.