Why is notepad unreadable?

Notepad files can be considered "unreadable" if they contain data in a format that the text editor cannot interpret, such as binary data or unsupported character encodings. Additionally, if a file is too large or contains complex formatting not suitable for plain text, it may appear jumbled or nonsensical. Lastly, if the file is corrupted or has been saved with incompatible settings, it may also render the content unreadable.