1-There is no "right" way to differentiate.  Every classroom is different, and children are different. This is why we differentiate for them.
2- Differentiation is simply meeting the needs of your students, whatever those needs may be.
3- There are going to be certain pieces of your lessons that need to be differentiated for different students.  You can still teach a lesson to the whole class.
4- Your idea of how to differentiate for your students will evolve as you get to know them better.
5- Differentiation maximizes your effectiveness as a teacher.
6- It is an effective marriage between the needs of your students and the demands on your job to teach curriculum.