1. A precise set of steps that can be used to solve some problem.
Source: Asking the Right Questions about Electronic Voting, Election Cybersecurity 101 Field Guide – Glossary, National Research Council on the National Academies, https://www.nap.edu/catalog/11449/asking-the-right-questions-about-electronic-voting
2. A procedure or formula that produces predictable, consistent results when applied. An algorithm describes, in formal language (frequently mathematical) how a problem is solved. An algorithm, like a recipe, is a well prescribed sequence of steps designed to produce a solution. The procedure that produces a uniform distribution of ordered candidates within a race in a ballot rotation scheme is an algorithm. Counting votes in an instant runoff voting system requires a specific algorithm.
Source: Information Technology Terminology, U.S. Election Assistance Commission, https://www.eac.gov/documents/2017/09/21/information-technology-terminology-security
3. A sequence of actions to perform to accomplish some task or solve a technical problem; the term is often used in the context of computer programming.
Source: Independent Panel on Internet Voting British Columbia, https://elections.bc.ca/docs/recommendations-report.pdf