Reproducibility has been consistently identified as an important component of scientific research. Although there is a general consensus on the importance of reproducibility along with the other commonly used 'R' terminology (i.e., Replicability, Repeatability etc.), there is some disagreement on the usage of these terms, including conflicting definitions used by different parts of the research community. In this encyclopedia article, we explore the different definitions used in scientific literature (specifically pertaining to computational research), whether there is a need for a single standardized definition and provide an alternative based on non-functional requirements. We also describe the role of reproducibility (and other R's) in scientific workflows.

7 pages, no figures. Submitted as an entry to the "Encyclopedia of Mathematical Geosciences."