Imagine you are playing with your friends outside and you see someone who is hurt and needs help. You want to help them and make sure they are okay. This is what humanitarian workers do too, but on a bigger scale.
They go to different countries and communities where people have been hurt or are in need of help. They give food, medicine, water, shelter and other things to help people. Sometimes, they even risk their own lives to provide this help.
However, some people do not like this help and they try to stop the humanitarian workers from doing their job. They might hurt them or even kill them. This is not okay and it is called an attack on humanitarian workers.
When these attacks happen, it makes it harder for the humanitarian workers to do their job and help people who really need it. We need to protect these workers and make sure they can continue to help people in need without any harm.