Can I turn a Contact into a Job and vice versa?

Contacts and Jobs navigate through separate Workflows while working in conjunction with one another.

While creating a Job under a specific Contact will auto-fill some of the information for your convenience, a Job cannot be turned into a Contact, nor can a Contact be turned into a Job. 

Jobs and Contacts belong to entirely separate Workflows and can never go through the same Statuses as the other.

You'll also notice that there are two Board views: one for Contacts, and one for Jobs. Contacts will not show up under a Job Board, nor will Jobs appear under a Contact Board.