 The author would like to acknowledge the contributions of Alejandro Vesga to this entry. He brought to my attention recently published papers on knowledge-how; brainstormed with me about the structure of the entry and the order of the topics to be discussed; provided substantial criticisms of, and suggestions for, drafts of the content; contributed the idea of adding a final section that related knowledge-how to other related topics; and compiled the bibliography once the bulk of the entry was finished.