Long sentence: An outline is a plan or blueprint for a written work, while a draft is a preliminary version of that work. The outline provides the overall structure and organization of the written work, while the draft fills in the details and elaborates on the ideas presented in the outline. In other words, the outline is a guide or roadmap for the draft, which helps the writer stay on track and ensure that their ideas are presented in a logical and coherent manner.
Short sentence: An outline is a plan, while a draft is a preliminary version that fills in the details of the plan.