What is the purpose of creating tension in a story

go to crash course lititure and go to seconed page and it shows a video about that

the teacher i would like to have must be a kind, caring and understandable teacher. she should be interactive with us and always plan fun activities to in our studies. she should be a teacher who would correct our mistakes when we do something wrong and guide us if we are weak. she should always be strict if we do something bad but must be praising us when we do something good. she she not take any as her favorite in her class but take everyone as her favorite.

(i hope this will u if there is something send me a reply)