An LLC typically defaults to being classified as a partnership. There are a number of different types of partnerships.
Units in partnerships typically represent percentages of ownership. For example, one (full) unit would normally be considered 1% ownership in the partnership.
If you have only one other partner and your articles do not specify otherwise, then you can consider your partnership to have 100 units (totaling 100%) and you each have 50 units if you have equal ownership.
