These terms are often used together, for example, in instructions. Both of them have Latin origin. Compare comes from comparare, meaning to liken or compare. Contrast comes from contra + stare, meaning against + to stand. This information suggests that compare refers to the relative value of the objects in all qualities, while contrast means to look at the dissimilarities between two (or more) things. Although, compare is about to find similarities, it can trigger the meaning of contrasting the items as well, after finding the similarities. To put it differently, compare explains how two or more things, groups and so on are similar, while contrast emphasizes the differences between them. Briefly, compare is about the similarities, contrast is about the differences.
