A text file is a digital document that primarily contains text data without any complex formatting or multimedia elements. In children's book contexts, text files may include manuscripts, drafts, or outlines for stories, made easy to edit or share across platforms. They often use formats like .txt or .doc and can be created in various text editing software. Text files are crucial for authors, editors, and publishers as they provide a straightforward way to manage and revise written content throughout the book creation process.