What is intertextuality?

Intertextuality is about the relationships between literary texts and how they can be interconnected. This applies to all texts: novels, works of philosophy, religion, newspaper articles, films, songs, paintings, and more. In order to understand intertextuality, it’s crucial to understand this broad definition of the word “text” and that every text is affected by all the texts that came before it.

Intertextuality shows how much a culture can influence its authors, even as the authors in turn influence the culture. When you create a work of art, literature, or scholarship, you are inevitably influenced by everything that you’ve seen or read up to that point. Even seemingly disparate fields, such as music and philosophy, can exert a strong influence on each other through intertextuality. Similarly, authors from different cultures and historical periods can influence each other!

Intertextuality also shows how a similar cultural, religious, political, or moral ideology can be expressed in very different ways through different cultural practices.

Source: https://literaryterms.net/intertextuality/