Text complexity refers to the level of difficulty in understanding a written piece. It is influenced by factors such as vocabulary, sentence structure, and the themes presented. Texts can be categorized as simple, moderate, or complex based on these elements, which affect how easily readers can comprehend the material. Educators often assess text complexity to match reading materials with students' abilities. Tools like the Lexile Framework or Fry Readability Graph help determine a text's complexity level. By understanding text complexity, teachers can provide appropriate resources that challenge students while still being accessible.