File explorer allows you to do simple file manipulation. It is a utility as on its worn it does very little. It can do the following main functions -

• Move files from one directory to another
• Copy files
• Rename files
• List/View directory contents

It can not open the files. This is the responsibility of the program associated with the file. For example in the windows family of operating systems the .doc file type is associated with Microsoft word. As such it is word which opens the file and not actually file explorer.