So imagine you and your best friend really love playing in your backyard. But then one day, some other kids start coming into your backyard and trying to take your toys and make you play their games. This makes you and your friend really upset and you want them to leave and go play somewhere else.
Now imagine that instead of a backyard, it's a whole country. When people from another country come in and try to take over, or make the people there do things they don't want to do, it can cause a lot of problems and make the people in that country upset.
In Islam, there is a concept called dar al-harb, which means "house of war". This term is used to refer to any place or country where there is conflict or war between Muslims and non-Muslims. It is not a happy or peaceful place, because there is fighting and disagreement happening.
Some people might use this term as an excuse to justify violence or aggression towards non-Muslims, but that is wrong. Just like in your backyard, it's not right to hurt people or take things from them just because they are different. It's important to learn about different cultures and religions, and try to respect everyone's beliefs and ways of living.