Genie is also living beings like we humans, but they are made of fire. Also they are 100 times stronger and powerful and so if conquered by us humans, then they become our slaves and we will be their master and they can do every thing for us. They are invisible and can be seen only by the master who will do the invocation and will conquer the genie. As God has given us humans to conquer any thing, even wild animals like lions and tigers in the circus are controlled by humans, and so by proper genie invocation you can conquer them and then live a happy and rich life.