We use the formula tener + que + infinitive when expressing obligation or necessity. So this translates into the English expression as have to have. Moreover, we can translate this formula as someone has to do something. Tener is an infinitive verb, but in sentences we conjugate it matching the subject pronoun of the sentence. For instance:
It looks like a family tree. Maybe described or names the parents of El Abuelo and La Abuela . And maybe name the children of the grandparents and the children of the parents. Hopefully that makes sense.
