Positions define the staffing structure of your organization. Positions are managed separate from your personnel so that you can decipher whether you have open positions in your organization to fill or not.
There are multiple ways for managing positions. You may want one employee per position where you can easily see openings when employees leave or transfer. On the other hand, you may want to assign multiple people into a single position when you do not need to differentiate the position in any way. If the same position resides in different work buildings, you may want to consider setting up a position by building and then assign multiple people into it. You will need to decide what works best for your HR management process.
As a note, positions that are assigned to employees are referred to as Jobs or Job Assignments in PeopleWerksHR. It is important to understand this differentiation of Positions and Job Assignments.