The document discusses different types of internal text structures that help readers understand and access information more easily from non-fiction texts. It identifies five main types: definition/description, which uses examples and restatements to define complex terms; problem-solution, which states an issue and suggests ways to address it; sequence/time, where changing the order of details would alter the meaning; comparison and contrast, which points out similarities and differences between topics; and cause and effect, showing relationships between causes and resulting effects. Signal words are provided for each type to help identify them.