Redaction is a form of editing in which multiple source texts are combined (redacted) and altered slightly to make a single document. Often this is a method of collecting a series of writings on a similar theme and creating a definitive and coherent work.
The term is also used to describe removal of some document content, replacing it typically with black rectangles which indicate the removal, although this usage was not documented by authorities such as the Oxford English Dictionary as of 2016, though earlier editions gave only this definition. For example, originally classified documents released under freedom of information legislation may have sensitive information redacted in this way. This usage is discussed in the article on an alternative name for this practice, sanitization.
On occasion, the persons performing the redaction (the redactors) add brief elements of their own. The reasons for doing so are varied and can include the addition of elements to adjust the underlying conclusions of the text to suit the redactor's opinion, adding bridging elements to integrate disparate stories, or the redactor may add a frame story, such as the tale of Scheherazade which frames the collection of folk tales in The Book of One Thousand and One Nights.
Sometimes the source texts are interlaced, particularly when discussing closely related details, things, or people. This is common when source texts contain alternative versions of the same story, and slight alterations are often made in this circumstance, simply to make the texts appear to agree, and thus the resulting redacted text appears to be coherent. Such a situation is proposed by the documentary hypothesis, which proposes that multiple redactions occurred during the creation of the Torah, often combining texts, which have rival political attitudes and aims, together; another example is the Talmud.
Redactional processes are documented in numerous disciplines, including ancient literary works and biblical studies. Much has been written on the role of redaction in creating meaning for texts in various formats.