subjects that have to be studied at a school or college:
the national core curriculum
the core subjects of English, maths, and science
Schools have to deliver the core skills.
the main business or activities of a company or organization:
The core business of airlines is flying people and cargo from place to place.
the company's core product
the values or beliefs that are most important to someone:
the core values of American liberalism, such as taxing the rich to help the poor