The Common Impact Data Standard is a standardized way to represent an organization’s impact model and five dimensions of impact. It allows social purpose organizations (SPOs) to store and report on impact data and accommodate the reporting needs of diverse funders. To store and report this data, SPOs don’t need a technical understanding of the Data Standard; they just need to use an aligned software. In this document, we define what we mean by the terms used in the Data Standard so that SPOs can better understand what data an aligned software can store and report at the Basic Tier.