A curriculum is an educational plan usually created with input from the district, school and teacher who will teach a given subject. In general, a curriculum teaches the skills and knowledge required for that grade's subject and year. The goal with any curriculum is that students learn the material that the teacher plans and teaches following the curriculum.
What is taught and learned in a curriculum varies by subject. In a biology class, the curriculum concerns the study of living organisms, whereas in an American history class, the curriculum might cover the colonial settlements of the 17th century. In theory, if the teacher is teaching effectively, students should learn what is being taught, making the taught and learned curricula essentially identical.
Increasing emphasis on universal teaching standards such as those found in the Common Core Standards and the Danielson Framework for Teaching makes it easier to see to what degree a teacher's planned and taught curricula meet the expectations of school districts and the needs of students. The exact curriculum plan, however, can still vary greatly from classroom to classroom. For example, a school district might set a standard requiring 9th graders to be able to locate and discuss the theme in a work of literature. Different classes might use different books to meet this standard, and different teachers might use different tools for teaching, such as worksheets, journals or in-class discussions.