Leadership styles and theories

[Aayman]

Hey everyone,
In 2017 psychology paper, there is a question:

"What are different leadership styles with reference to major leadership style theories? Elaborate the characteristics of transformational and transactional leaders with appropriate examples."

the syllabus says,"Leadership styles", The internet search on these two topics leads to independent results, If I search for theories, the styles are not mentioned and I search for styles, theories are not there.(My point is, the question demands us to know the two in relation to each other and that I am unable to find)

so I need help regarding this topic.Anyone who is planning to take Psychology in 2018, or has already had Psychology as an optional before or as your major subject, please guide me.
Thanks