In literary theory, text is anything that can be "read", whether it be a work of literature, a street sign, the arrangement of buildings on a city block, or the style of dress. It is an integrated set of symbols that transmits some kind of informational message.  This set of symbols is understood in terms of the content of the informational message, rather than its physical form or the medium in which it is represented.
In the field of literary criticism, "text" refers to the original informational content of a particular text. That is, the "text" of a work is the basic symbolic arrangement of letters as it is made later, except for later changes, distortions, interpretations, translations, para-texts, etc., when literary criticism relates to the determination of "text". ", It relates to the distinction between the original information content and what has been added or subtracted from the content as it appears in the given text document (i.e. the physical representation of the text).
Because the history of writing predicts the concept of "text", most writings are not written with that concept in mind. Most writing works fall into a narrow range of types defined by text theory. The concept of "text" becomes relevant if and when the "integrated text message" is completed and needs to be referenced independently of the circumstances in which it was created.