Reviewing and reflection are two methods of thinking about anything that you have just recently learned. Reviewing can of course be undertaken mere moments after a question has been posed, a passage has been read, directions have been given, a comment has been made or an activity has been performed, allowing some time to be given over to think about what has just taken place, to process that information and then to react in an appropriate manner.
Reviewing also needs to be undertaken at periodic intervals over the course of a year, so that students have the chance to be able to revisit, clarify, relearn and then consolidate what they have learned to memory.
Reflection meanwhile encompasses not just the way the actual material is or has been responded to, but also taking into account the way in which one actually goes about the process of learning in the first place.