The difference between management and leadership, according to WorldWideLearn, is that management consists of doing things right, and leadership consists of doing the right things. While all businesses need to be managed, the term "management" generally refers to the day-to-day nuts and bolts of getting things done. Leadership is a bigger concept. Leaders take a company in a direction that is both successful and consistent with its mission, moral values and work ethic.
To get a doctoral degree in any field, a student must already have related educational experience. At least a bachelor's degree, and usually a master's degree, is required before you can seek a PhD. For a leadership PhD degree, a master's degree in business, business management or a related field would generally be best. Each PhD program lists the degrees it accepts.
A PhD in leadership is primarily an online degree. You can earn one from a variety of schools as an online or distance learning degree. However, many schools don't even have a physical campus to attend, so make sure about the school's requirements and educational resources before you start paying your tuition and taking your classes.
It's important before you sign up that you determine what employers accept the PhD in leadership you're seeking. The school should have a list of standards the degree meets, and of employers that consider it valid. Make sure you're not paying money and putting in time and effort to earn a degree that won't advance your career or make you a more valuable employee.