Text complexity refers to the level of difficulty and sophistication in a text. It is an important measure used by educators, publishers, and parents to determine if a book or other written material is appropriate for a particular age group or reading level. Text complexity includes factors such as vocabulary, sentence structure, and themes that may be challenging for some readers. The goal of measuring text complexity is to ensure that students are being exposed to materials that will challenge their thinking while also being accessible enough for them to comprehend and enjoy.