There are two kinds of WP Backup
1) Manually Backup
For the manually backup you need
a) the export of the database (you can use PHPMyAdmin and then FTP via FileZilla the file to your laptop
b) from public_html > Dir of WP> three folders named wp-admin, wp-content, and wp-includes
c) some other files like .htaccess, wp-config.php (some people take backup of all files of WP root dir, maybe to need more files from a specific installation like JS, stand-alone pages, e.t.c.) Everything that has anything to do with the look and feel of your site is in a file somewhere and needs to be backed up.
In order to restore you need to edit with Notepad++ the DB file and change the paths to the new env.
make a clean install of WordPress and
copy the three dirs wp-admin, wp-content, and wp-includes
import the DB file that you have modified with Notepad++
the wp-config.php must have the new DB name and new password and user info
2) Via a plugin or the Hosting Backup
this can be FREE or PAID
it also can be FULL or INCREMENTAL ( only the new data from the time of the last backup)
Make your tests and PLEASE read the OFFICIAL WordPress Backup DOCUMENTATION
see WordPress Backup