A scientific community needs well-defined and agreed-upon concepts with related terms as a basis for a sound academic discourse. The field of IT standards and standardization research is still developing in this direction. This Chapter aims to contribute to this process by proposing a definition for the area of research as well as classifications of IT standards. It appears that classifications of standards can be based on the subject matter concerned, on the process of developing the standards, or on the intended use of the standards. IT standards are IT standards because of the subject matter addressed in the standards. The Chapter concludes by discussing how the scientific as well as the professional IT standardization community might use the findings.