2. What is the different between gaol, aim and objective in education?

These terms are kind of interchangeable. I suppose objectives might "lead the way" to a broader goal. Objectives tend to have integrated steps to achieving a goal like say graduating in High School. I think aim is a specific target one might want to achieve in education on the way to realizing the goal. An example might be getting an A in English 11. As I said though, the words are interchangeable.