SQL Server Database Backup and Restore Planning
Source: AppAssure Software
In simple terms a backup is a copy of the data contained within a system. For a DBA, a backup can consist of either a single file or multiple files for one database to the entire server. These files can be classified into three types: a full backup, a partial or differential backup, and finally, a transaction log backup. By utilising all three types of backups, the amount of data that needs to be backed up at specific times and the overhead placed upon the hardware to complete the backups at critical times is reduced.