What is differentiation, and what does it mean for me as a teacher?
Differentiation means that you consider the wide variety of abilities and learning styles of your students when planning lessons, activities, and assessment so the each student does challenging,  meaningful work.  Your students have options for how they acquire information, locate and analyze information, and show what they know.  The instruction is student centered, and they are frequently given the opportunity to work independently or with a group of students who have similar abilities or interests. 

Here are some characteristics of a classroom where differentiated instruction is used:
 
• The teacher is clear about key concepts and skills in content areas.
• All students participate in respectful work.
• The learning goal is to create maximum growth and individual success.
• Flexibility is the hallmark.
• The teacher adjusts content, process, and product in response to student readiness, interest, and learning profile.
• The teacher understands, appreciates, and builds on student differences.
characteristics provided by Dr. Sally Walker
For more  information
Basics of Differentiation by Carol Tomlinson
Differentiating Instruction For Advanced Learners In theMixed-Ability Middle School Classroom By Carol Ann Tomlinson ERIC EC Digest #E536, October 1995