Have you ever heard of real estate? It's when people buy and sell houses and buildings to each other. Mobbing is when a group of people are mean to one person and make them feel scared or uncomfortable.
Now imagine, people who want to buy a house or apartment decide to be mean to the current owner to try and make them sell the property for cheaper. This is called real estate mobbing. They might do things like make loud noises, damage the property, or be really annoying to the person who is trying to live there.
This is not a nice thing to do, and it can make people feel really scared and unsafe in their own homes. It's like being in a playground where the big kids are bullying you and you can't escape from them. It's not fair and it's not right. People should be kind and respectful to each other, especially when it comes to their homes.