mysqldump tool provide facility to backup MySQL databases. It creates *.sql file with DROP, CREATE and INSERT statements. There are number of keys, which can be used to create backup of database(s).
Details of all keys can be checked using command
bash: # mysqldump --help
Basic command for taking backup
bash: # mysqldump -u root -p[root_password] [database_name] > filename.sql
And for restoring
bash: # mysql -u root -p[root_password] [database_name] < filename.sql