How can I use knowledge of the learner to be a better teacher?

I feel like the most useful chapter that we have done, in relevance to this question, is chapter 2. This was the chapter about today's students. The students with disabilities, different economic status's, gender, religion, English language learners, and racial differences. This answers this question most because it shows us all the different situations that might present themselves to us as teachers, and when we can recognize these differences we can help alter lesson plans and make the situation better all around. Will all of the differences we've learned about I still don't know how to handle and understand different types of parents. I feel that understanding the parents is an essential piece to understanding and helping the learner.