Yad Vashem is kind of like a big museum that helps us remember and honor the people who suffered and died during a really sad and scary time in history called the Holocaust.
The Holocaust happened during World War II when a man named Hitler and his followers, called Nazis, wanted to get rid of Jewish people and others who they didn't like. They did really bad things to these people, like making them leave their homes and sending them to special camps where they were treated very poorly and even killed.
Yad Vashem is in Israel and it is a special place where people can go to learn about what happened during the Holocaust. The museum has lots of exhibits and documents, which tell the stories of people who lived during that time.
It's also a place where we honor the people who did good things during the Holocaust, like helping to hide Jewish people so they wouldn't be found by the Nazis. These brave people are called "Righteous Among the Nations" and we remember their actions and bravery at Yad Vashem too.
So, Yad Vashem's goal is to help us remember and never forget what happened during the Holocaust, and to honor the people who suffered and those who did good things to help others during that time.