Which statement accurately describes a Boolean operator that combines keywords for focused searches?

The choice of "Boolean operator" as the accurate descriptor for an operator that combines keywords in a focused search is correct because Boolean operators specifically refer to logical operators like AND, OR, and NOT. These operators allow users to refine search queries by establishing relationships between search terms, thereby increasing the relevance of the search results.

For instance, using AND between two keywords ensures that the search results will include only the documents that contain both terms, which narrows down the results to the most pertinent ones. Meanwhile, OR broadens the search results to include documents that contain either of the terms. NOT excludes certain terms from the search, further filtering the results.

This specificity in search operations underscores the pivotal role of Boolean operators in information retrieval processes in computer science and search engine functionality. The other options do not convey the same applicability: exclusive operator and arithmetic operator are not relevant in the context of keyword searching; thus, the distinction of Boolean operators stands as the most accurate and relevant choice.