In my experience, creating personas is a process of using specific parameters to group and differentiate customers.
Sometimes parameters are straightforward, like when you're using basic demographics or occupations, while other times they're much more complex, like when you're trying to connect specific behavioral characteristics to the pain points your product/service addresses.
The result is that one project might call for 4 broad personas: Sales Rep, Marketing Manager, COO and CEO; while anothe might include a set of personas that all revolve around the same core occupation, like CEO.
These examples highlight five different kind of CEOs you might target:
The Administrative CEO
The Entrepreneurial CEO
The Social CEO
The Competitive CEO
The Technical CEO