A backup refers to copying and archiving computer data so it can be restored after data loss. There are different types of backups including full, incremental, and differential backups. Backups can be stored on magnetic tapes, optical disks, hard disks, or remote access services. Successful backups start by selecting files from file systems and saving metadata describing the computer and file system. Common backup techniques are compression, duplication, encryption, and multiplexing.

1. A Backup, or the process of backing up, refers to the copying and archiving of
computer data so it may be used to restore the original after a data loss event.
The verb form is to back up in two words, whereas the noun is backup

2.  Full Backup
 Incremental Backup
 differential backup

3. Magnetic Tape
Optical storage
Hard disk
Remote Access Service
Floppy disk

4. Near line
Off line
On line
Back site and disaster recovery center

5. A successful backup job starts with selecting
and extracting coherent units of data. Most
data on modern computer systems is stored
in discrete units, known as files These files
are organized into file systems . Files that are
actively being updated can be thought of as
"live" and present a challenge to back up. It is
also useful to save metadata that describes
the computer or the file system being backed
up.

6. Compression
Duplication
Encryption
Multiplexing

7. thank
you