A periodical collection of messages which have been posted to a newsgroup or mailing list. A digest is prepared by a moderator who selects articles from the group or list, formats them and adds a contents list. The digest is then either mailed to an alternative mailing list or posted to an alternative newsgroup.
Some news readers and electronic mail programs provide commands to "undigestify" a digest, i.e. to split it up into individual articles which may then be read and saved or discarded separately.