The aim of this primer is to provide assistance to the Judiciary, legal professionals and lay persons in understanding error rates in fingerprint examination. The document aims at defining the types of errors that may be presented in courts and explaining their meaning and limitations, both to assess the discipline as a whole or assess the proficiency of a specific expert in a given case. At the end of the document, it is illustrated by an example of a brief conversation between a member of the Judiciary and a fingerprint expert. It is part of the deliverables associated with the project "Testing the Accuracy and Reliability of Palmar Friction Ridge Comparisons: A Black Box Study", a project supported by Award No. 2017-DN-BX-0170, awarded by the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice. The opinions, findings, and conclusions or recommendations expressed in this publication/program/exhibition are those of the author(s) and do not necessarily reflect those of the Department of Justice.