Each student's work should be equally interesting, equally appealing, and equally focused on essential understandings and skills. Rather, everyone is continually working with tasks that students and teachers perceive to be worthwhile and valuable. Flexible grouping is a hallmark of the class. Teachers plan extended periods of instruction so that all students work with a variety of peers over a period of days. In addition, teachers can assign students to work groups, and sometimes students will select their own work groups.
Teachers are as different as their learners.
Some teachers naturally and robustly differentiated instruction early in their careers. For other teachers, establishing a truly flexible and responsive classroom seems daunting. It is helpful for a teacher who wants to become more effective at differentiation to remember to balance his or her own needs with those of the students. Once again, there are no recipes. Look for matches and mismatches, and use both to guide you.