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:warning:Storage Devices and Media :desktop_computer: (Deifinations…
:warning:Storage Devices and Media :desktop_computer:
Type of access
Direct/random access
The computer calculate exactly where the data has been stored and can go straight to it directly.
Used in DVDs and hard disk drives
Used in online booking systems and point of sales (POS)
Serial/sequential access
Data is accessed by starting at the beginning and then searched through in order /sequence until the required information is found
Used on old magnetic tapes. Which are still used in schools and big organisations
Used in batch processing systems like payrolls and bills.
Deifinations
Storage device
It is the device that writes and reads the data.
Storage medium
Is the 'permanent storage' and will hold data even when the computer is shut down.
Can be permanent/non-volatile or temporary/volatile
Storage
Data storage is where we put data in a "known" place(save) which we can come back to later and get the data back again (read)
Backup
What is backup?
Backing up is the process of using a storage device to copy files and data to a different storage medium in case of a problem with the original copy.
Why backup data?
Original data could be accidentally copied over or deleted
Data could be lost due to the damage to the original storage device
You could lose your original storage device
Hackers can access to your data and delete it (or change it)
Original storage device could be destroyed in fire or natural disasters
Storage capacity
Binary system
Binary system is a system in which information can be expressed by combinations of the digits 0 and 1
.
BIT(short for binary digit) is the smallest unit of data in a computer. A bit has a single binary value, either 0 or 1
.
BYTE is a unit of digital information that most commonly consists of eight bits.
