Comparison, contrast, antithesis, collation, parallel mean a setting of things side by side so as to discover or exhibit their likenesses and differences, especially their generic likenesses and differences.
Comparison is often used as the comprehensive term; it is preferred when the differences are obvious, and an intent to lay bare resemblances and similarities for the sake of expounding or judging is implied. Because measuring one thing in terms of another is usually implied by comparison, the word often imputes an offensive character either to the association or to the judgment.
Contrast more specifically implies an intent to distinguish or discriminate things which are so much alike that their differences are not obvious.
Contrast often also suggests an aesthetic rather than an expository aim or an artistic effect gained by the exhibition of startling differences.
Antithesis also implies contrast for the sake of revealing startling differences, but it distinctively suggests such opposition in the things contrasted that they either represent balancing extremes or negate each other. The word may imply an expository intent; it then presupposes that the true nature of one thing is fully understood only when it is presented as opposed to what is unlike it in every particular.
Collation and parallel denote a kind of comparison for the purpose of revealing both likenesses and differences. Both imply a close study and usually a specific aim.
Collation more specifically implies a comparison of different versions, accounts, editions, texts, or manuscripts of the same thing for the purpose of verification, coordination, correction, or selection of the original and parallel usually a minute comparison of passages, articles, or works which are believed to have a different origin in order to detect correspondences, or of accounts, records, or stories told at different times which ought to agree, in order to detect discrepancies; thus, by what is often called “the deadly parallel,'” a comparison of two articles may reveal such correspondences in language and thought as to give ground for a charge of plagiarism, or a comparison of testimony given by the same witness on two occasions may reveal discrepancies that make him liable to arrest for perjury.