The document discusses the infinitive of purpose. A verb in the infinitive form can be used to indicate purpose, similar in meaning to using "para" in Spanish. Examples are provided, such as "I need these books to study for my exam" and "This button is to save the file in your computer", which could be translated as "Necesito estos libros para estudiar para mi examen" and "Este botón es para guardar el archivo en su computador".