Disciplines are made up of many parts.
First, and most obviously, there is the content of the discipline. Content is generally what is “covered” by coursework in the discipline. It can include facts, concepts, ideas, and texts. Content is the what of a discipline.
Second, there are the methods of the discipline. Methods are the way that we study the content of a discipline. It is the how of a discipline. For example, your disciplines may be primarily quantitative, using numbers, measurements, and empirical research to understand its content. Or your disciplines may be primarily qualitative, using interviews, case studies, and observations of human behavior to understand its content. Some disciplines use a mix of these methods. Sometimes a discipline’s methods are referred to as methodology. In the case of a research project, you might be expected not just to explain your findings, but also to explain your methodology, or how you reached your findings.
Third, there is the epistemology of the discipline. This is tied to both content and methods. An epistemology is a worldview, ideology, or approach to truth and knowledge. For example, in math, the dominant epistemology is one of logic and objectivity. Truths are independently verifiable, and they can be ascertained by anybody who has learned how to apply the formulae. In literature, however, the dominant epistemology is one of subjectivity and relationships. The meaning of a sentence will depend on its relationship to other sentences, and the meaning of a short story will be up for debate depending on the evidence that individual readers assemble. In some ways, epistemology explains the why of a discipline: why it focuses on certain content and why it chooses the methods that it chooses.
Disciplines have other aspects as well, such as theories and assumptions. But content, methods, and epistemologies are the central building blocks of disciplines, and it is helpful to understand these as you get started in Interdisciplinary Studies.