Distillation is a general term for several different processes, all of them involving elevated temperature relative to the materials to be separated boiling points. It is generally a separation process, but in some cases actually involved chemical reactions to create new materials during the process.
Distillation as we generally think of it is a method used to separate two or more liquids, but it is much more general than that. It also is a term that is used, by extension, to take a large amount of information and extract the most pertinent parts of it into a concentrated form. Indeed, distillation is often used to concentrate a minor component of a mixture to pure (or at least more concentrated) material.