In PHPMyAdmin extract the database in .sql file includes and data and structure ? May an .sql file viewed in excel ? restore a database from .sql file can be done ?

In PHPMyAdmin the .sql files in the most common way backup all the database in phpmyadmin ?

yes, the .sql file can include both structure and data

no, you can view it in a text editor instead (e.g. notepad)

yes, you can restore from a .sql file

yes, this is a common way to back up tables