Is Account Name Required for Target?

We are trying to import a bunch of Targets into Sugar CRM. But each target has Account Name field. Do we need to assign some Account Name to Target? My understanding of Account is that, when a Prospect lead becomes a customer, he will become Contact and Account is Company Name of the Contact. So Account Name actually represents a Company of a Contact or Lead.

If we use Account Name for Target also, how do we identify the converted customers?