Yukl  defines transformational leaders as leaders with an appealing vision for their team and they intellectually stimulate others in a way that is demanding and appreciative of the individual needs of the team members, incorporating the four elements of Bass  in the definition.
Transactional leaders exert influence on followers based on exchanging benefits, this can be internal or external motivators, and respond to their self-interests when they achieve defined goals .
First of all, the model of Ha-Vikström  based on the theory of Blake, Shepard, and Mouton  shows three basic paths to think about leadership; relation-oriented or people-oriented leadership, task-oriented or goal-oriented leadership and laissez-faire leadership.
And second, the leadership model of Lewin, Lippit and White , describes autocratic, democratic and laissez-faire leadership.
A lot of research is based on the research done before and many different types of leadership are discussed in literature, as Suddaby  stresses.
This research aims to bring clarification to the most discussed types of leadership in the past five years.
The research method is a systematic literature review.
Systematic literature reviews started in the medical sciences and were developed because of a need to describe objective, generalizable and reliable data from literature on the application of medicine and treatment methods .
As the laissez-faire leader believes people are unpredictable and uncontrollable and understanding people is a waste of time, this leader maintains a low profile and works with whatever structure is available without any suggestions or criticism   .
The leadership model of Bass  shows a lot of similarities with two other well-known models of leadership.