A source text can be one of several different things, depending on the context in which the term is used. In literature, it can refer to the original version of a text that has been adapted or translated. Historians use the term to denote a piece of evidence on which a given historical argument depends. For a journalist, a source text is also a piece of evidence, although generally a contemporary one. Additionally, the term can also refer to a block of raw text that is fed into a computer program as input.
Works of literature are often translated or redacted for publication. When this is done, the original and complete source text of a work is generally reviewed in its original language. Translators work from this source text to produce translated versions of the text, and editors may shorten or modify portions of a text for reasons ranging from political necessity to space considerations. Scholars will typically prefer to study the original text of a work of literature, as each translation or redaction alters the meaning in ways ranging from the subtle to the profound.