How do you know the diffrence between love and a crush?

A crush wont last forever, its something that you first feel for someone for his outlooks, it makes you happy but it fades away in a while, love is something that lasts for an eternity, when you love someone you love him for who he is not for what he looks like, you are ready to give up everything for him and do everything so that he is happy. Love is a stronger feeling than a crush. We teens have a lot of crushes almost everyday, but we have to understant that a crush is just a strong attraction to someone, we might confuse it with love in our age because we have never felt these feelings before but love is such a strong feeling. If you love someone you are ready to sacrifice yourself for their happiness.