What type of data file can be opened and viewed in an editor such as notepad?

Text files, commonly with extensions like .txt, .csv, or .log, can be opened and viewed in a simple text editor such as Notepad. These files contain plain text without special formatting, making them suitable for easy editing and viewing. Additionally, some code files (like .html or .py) can also be opened in Notepad, as they are primarily text-based. However, binary files (like .exe or .jpg) cannot be properly viewed in Notepad, as they contain non-text data.