No. At the hardware level each file is a collection of bytes.
MS Word uses some byte patterns to indicate formatting and font information. Notepad is not written to deal with this information and will not work correctly with a file that contains it. This is somewhat like a book written in English and a book written in Latin. The same book shelf could hold both books and both books use the same characters printed on paper. But there is a software difference between the books.
A text file is a file that contains bytes that represent characters, and a limited number of other bytes that represent ends of lines, tabs, and a few other control characters. A text file contains bytes that represent:
Text files are the easiest type of files for a program to deal with.