An E-R model is usually the result of systematic analysis to define and describe what is important to processes in an area of a business. It does not define the business processes; it only presents a business data schema in graphical form. It is usually drawn in a graphical form as boxes ("entities") that are connected by lines ("relationships") which express the associations and dependencies between entities. An ER model can also be expressed in a verbal form, for example: "one building may be divided into zero or more apartments, but one apartment can only be located in one building."