Please enable JavaScript.
Coggle requires JavaScript to display documents.
Storage devices and media (Definition (Storage device : is the hardware…
Storage devices and media
Definition
Storage device : is the hardware that saves (writes) or reads the data from the storage medium . E.g : CD Port , USB Port
Storage medium : is the hardware that actually holds the data. E.g : USB , CD
Storage / Data Storage is where we put data into a known place (save) which we can come back to later and get the data back again (read)
Backup
Why Backup data ?
Original data could be accidentally copied or deleted
Data could be lost due to damage to the original device
3.You could lose your original storage device
4.Hackers could access our data and delete it
5.Original storage device could be destroyed
What is Backup ?
Backing up data is the process of using a storage device to copy files and data to a different storage medium
Type of access
Serial Access
Serial access is also known as sequential access , data is accessed by starting at the beginning and then searched through the data in sequence until the information is found , data is accessing is very slow . E.g : Magnetic tapes . The serial access is used in businesses for huge back-ups in batch processing system.
Direct access
Direct access is also known as random access , the data doesnt need to be read from the beginning to the end , it can easily find the data you want without searching all the data . E.g : DVD drives , USB . Direct access is used by people who do not require that much of backup
Byte
A group of binary digits or bits (usually eight) operated on as a unit
A byte is considered as a unit of memory size
Binary system
A system in which information can be expressed by combinations of the digits 0 and 1 it is also a system containing two parts
Relation between bytes and bits
8 bits = 1 byte (B)
1024 bytes = 1 Kilobyte (KB)
1024 Kilobytes = 1 Megabyte (MB)
1024 Megabytes = 1 Gigabyte (GB)
1024 Gigabytes = 1 Terabyte (TB)
