yes, you can do it, because the Database Contain all your Posts ...etc So to do you can make a backup through phpmyadmin or you can use a Plugin called WP-DB-Backup Goodluck
Absolutely, There is a free plugin called WP DB Backup. Check wordpress or do a google search. I use it to email my weekly backups.
1) login to your wp admin panel and clicl tools - > export it gives all posts , categories , tags. 2) take backup in phpadmin or using mysqldump (this saves entire blog str like links , plugins options etc )
1 - Login into wp admin and click tools > export. save xml file of wp posts backup. 2 - go to phpadmin under ur cpanel > select ur db > export > charachter set for file utf8 > save and u r done. 3- wp database backup plugin http://wordpress.org/extend/plugins/wp-db-backup/