What term is used for a clearly defined educational aim that a student is supposed to reach?

The term that best describes a clearly defined educational aim that a student is supposed to reach is "objective." Objectives are specific, measurable statements that articulate what a student should know or be able to do by the end of a lesson, unit, or course. They serve as a guide for both instruction and assessment, ensuring that the focus is on the desired educational results.

While "outcome" and "goal" might seem similar, they do not capture the specificity that an objective entails. An outcome generally refers to the end results of education that can encompass broader aspects of students' growth or development, while a goal is typically a general aim without the specific details necessary for educational planning. Standards, on the other hand, are often broader expectations set by educational authorities that outline what students should know and be able to do at various stages of their education but do not focus as precisely on individual learning outcomes for specific lessons or activities as objectives do.