The Overlap Coefficient is a statistical measure used to quantify the similarity between two sets. It calculates the size of the intersection of the sets divided by the size of the smaller set. This coefficient ranges from 0 to 1, where 0 indicates no overlap and 1 indicates complete overlap. It is particularly useful in fields like information retrieval and bioinformatics. In practical terms, the Overlap Coefficient helps in comparing the contents of two lists or groups. For example, if two documents share several keywords, the Overlap Coefficient can indicate how closely related they are based on those keywords. This measure aids in tasks such as document clustering and recommendation systems.