Differentiation ensures teaching and learning will be tailored to students in order to maximize their individual growth. Below is a quote from a leading researcher in this area:
“Differentiation is simply a teacher attending to the learning needs of a particular student or small groups of students, rather than teaching a class as though all individuals in it were basically alike.” ~ Carol Ann Tomlinson
Differentiation Central
North Carolina Center for the Advancement of Teaching - Differentiated Instruction Videos
Scholastic: What Is Differentiated Instruction?
Reading Rockets: What is Differentiated Instruction?