NotePad:

• A notepad is a simple text editor tool that comes with windows by default.
• It support almost all the languages.
• It saves the file with .txt extension.
• No individual line selection / line numbering
• Can edit most files
• File extensions have to be typed

Notepad++

• Notepad++ is a free source code editor which is a replacement of the notepad
• It additionally supports more languages
• Tabbed documents, spell checker, file comparisons, zooming and the find and replacement feature make it much more attractive
• Currently, there are 27 official plugins for Notepad++ that can be used to enhance the features of the application
• Line selection / line numbering
• Can edit all of them
• File extensions can be selected from a menu

How to set Notepad++ as default app in Windows 10