Storage Flashcards
What is RAM?
Random Access Memory
Stores data and instructions currently in use
Data can be read AND written to RAM
Volatile - data is lost when computer is turned off
What is ROM?
Read Only Memory
Used to store instructions that don’t need to be changed during normal use
Data can only be READ from ROM
Non-Volatile - retains data when power is turned off; is used to boot up computer
What is cache memory?
Very fast memory
Stores recently of frequently used instructions
Very EXPENSIVE
Why is secondary storage needed?
Used to transfer data from hardware to CPU
3 types of secondary storage?
- Magnetic
- Optical Storage
- Solid-State Memory
Where is MAGNETIC storage used?
Hard Disks
Average size of a MAGNETIC storage device?
1 Terabyte
Where is OPTICAL storage used?
- CDs (700MB)
- DVDs (4.7GB)
How is data stored in OPTICAL storage?
Stored along the 5km track by etching PITS into the surface of the disc by using light produced by a laser
Where is SOLID-STATE memory used?
- Sold State Drives (SSDs)
- SD cards
- USB flash drives
What is flash memory?
Non-volatile memory that can be electrically erased and reprogrammed
What is cloud storage?
Off-site storage made available to users over a network
Advantages of cloud storage?
- Data will be safe if the original data is destroyed
- Data can be accessed from anywhere with an internet connection
- No need for an expensive storage device
- Able to collaborate with users across the world
- Data can be synced across devices as it’s updated
Disadvantages of cloud storage?
- Internet connection is needed for access
- Download/ Upload speeds affected by internet connection
- Hosting company could be targeted by hackers
- Less control if data is held by another company
- Storing some data online may breach the Data Protection Act as it should be kept secure and confidential
What is an embedded system?
Computer system built into another device in order to control it
