Intertextuality is a term introduced by Julia Kristeva and widely accepted by literary theorists to denote the complex way in which a text relates to other texts.
Just as there is no sign separate from other signs, there is no text separate from other texts.
In Kristeva‘s words, “every text is constructed as a mosaic of other texts, each text is an absorption and transformation from other texts. The idea of intertextuality replaces that of intersubjectivity.” (Kristeva 1969, 146).
The term intertext could mean text that refers to other texts and text that is indicated by other texts.
Sometimes this word also means a relationship between two texts or between several texts.