Many people would think that there is no difference and some may go as far as thinking that they are just different terms to describe the exact same thing but undoubtedly they are closely related to each other!
Instructional Technology is technology that primarily is applied to enhancing the communication of learning material. Anything that can add additional dimensions to the information, anything that can “bring it to life”, so to speak. It is best appreciated from the point of view of the instructor.
Educational Technology goes a step further and is applied to the enhancing the knowledge transfer, i.e the actual act of learning. Anything that can help ascertain that learning is actually taking place, anything that helps with information retention and recollection. It is best appreciated from the point of view of the student.