You can create text information if you want to provide supplementary information that relates to several questions. It is useful to create text information if you have several questions that need to reference the same passage and you want to avoid repeatedly writing the same text for each question.
For example, you may have a case study that you want to use as the basis for several questions. Instead of inserting the case study into each question, you can create a text information item and have related questions appear directly underneath it.