Reflection is used in many academic disciplines as diverse as health-related fields, such as Nursing, Midwifery, Radiography or Physiotherapy or Business studies, such as HR. In all of these fields, reflection is used as a tool to review practice in the light of theory and there are different models that can be used to guide this process. This means that in an academic context the meaning of reflection is slightly from the way we use the word in everyday life.
The Academic Skills Unit at Portsmouth University has produced a very helpful introduction to reflective writing. Click on this link and open the handout on Reflective Writing (13a).