Microsoft Word and Notepad are two software programs used for word processing. Word offers a wide range of formatting and publishing features and can create many types of files. Notepad, to the contrary, is simply a bare-bones text processor.
Notepad limits your document formatting to a font choice and whether or not to wrap the text. Word is a full-featured desktop publishing program, allowing control over every facet of the document's appearance and its features.
Notepad creates plain-text files that contain no hidden formatting commands. This is useful for building documents that are read electronically and would be confused by non-text characters. Word can save your documents in a wide variety of formats, including those of competing software products.
Internal vs. External
Word is an expensive software package that must be licensed and installed on your computer. Notepad is an internal program that is included with every Windows installation. It takes up much less memory and storage than Word.
Word contains an extensive spelling and grammar library that is automatically enabled as you use the software. It identifies possible misspellings and grammatical errors on the fly, and can be taught to spell new words as the need arises. Notepad does not have any of these tools, and will accept all spellings and grammar as you type.