1.2 memory and storage

• What are the two categories of storage in a computer system?

  Primary Storage and Secondary Storage
• Why is primary storage considered very quick?

  Because it is directly accessed by the CPU
• What is another name for primary storage?

  Main memory
• Which types of memory are included in primary storage?

  RAM and ROM
• What is the difference between volatile and non-volatile storage?

  Volatile storage is temporary and loses data when powered off, while non-volatile storage retains data without power
• Give an example of volatile storage.

  RAM
• Why do computers need primary storage?

  To allow the CPU to access program instructions and data quickly
• Give an example of non-volatile storage.

  ROM
• What happens to program instructions and data before they are processed by the CPU?

  They must be copied from the hard drive into RAM
• What is secondary storage?

  Non-volatile storage used to save and store data that can be accessed repeatedly
• Why is primary storage access faster than secondary storage?

  Because primary storage is internal and directly accessed by the CPU
• What does RAM stand for?

  Random Access Memory
• What type of storage is RAM?

  Volatile (temporary) storage
• Why is secondary storage slower to access than primary storage?

  Because it is further away from the CPU and not directly embedded on the motherboard
• What does ROM stand for?

  Read-Only Memory
• What information does RAM store?

  All programs that are currently running and parts of the operating system
• What type of storage is ROM?

  Non-volatile storage
• What are the key characteristics of storage you should know?

  • CAPACITY: Maximum data storage
  • DURABILITY: Strength of the device
  • PORTABILITY: Ease of carrying
  • ACCESS SPEED: Speed of reading/editing data
  • COST: Average price of the device
  • RELIABILITY: Likelihood of continued performance
• What is the most common form of secondary storage in desktop computers?

  Magnetic hard disk drive (HDD)
• What does ROM store?

  The boot program/BIOS for when the computer is switched on
• What is the role of the BIOS?

  To load the operating system to manage the computer
• What is an obsolete type of magnetic storage?

  Floppy disk
• How does a read/write head function in a magnetic hard disk drive?

  It moves above the disk platter and uses the magnetic field to read or edit data
• What is virtual memory?

  An extension of RAM using the hard disk drive
• Why are solid state devices like USB sticks preferred over floppy disks?

  They are much faster and have a higher capacity
• What is a characteristic of magnetic tape storage?

  It has a high storage capacity but requires serial access
• How does virtual memory work?

  Unused data in RAM is moved to the hard drive to make space for new data
• What are the characteristics of magnetic storage (Hard Disk Drive)?

  • Large CAPACITY
  • Cheaper COST per gigabyte than solid state
  • DURABLE and PORTABLE if modern external HDDs
  • Slower ACCESS SPEED than solid state but faster than optical
• How does optical storage read data?

  It uses a laser to project beams of light onto a spinning disc
• What are the differences between primary and secondary storage?

  • Primary Storage:
  • Very quick, directly accessed by CPU
  • Smaller in size
  • Includes RAM and ROM
  • Secondary Storage:
  • Slower, not directly accessed by CPU
  • Larger in size
  • Used for long-term storage
• What is a benefit of using virtual memory?

  It allows more programs to run simultaneously with less system slow down
• Why are optical discs considered not durable?

  Because they are fragile and can break or scratch easily
• What is the capacity of a CD, DVD, and Blu-ray disc?

  CD: 700 MB, DVD: 4.7 GB, Blu-ray: 25 GB
• What are the types of primary storage and their characteristics?

  • RAM (Random Access Memory):
  • Volatile storage
  • Stores currently running programs and parts of the OS
  • ROM (Read-Only Memory):
  • Non-volatile storage
  • Stores boot program/BIOS
• What does it mean to compress a file?

  To make its size smaller
• What is the primary number system used by computers to store data?

  Binary
• Why must data be converted into binary format for processing by a computer?

  Because all computer systems communicate, process, and store data using binary
• What is the process of using virtual memory?

  1. Programs stored in RAM for CPU processing
  2. If RAM is insufficient, data is moved to HDD
  3. New data is transferred into RAM
  4. Original data can be moved back when needed
• What are the benefits of file compression?

  • Files take up less storage space
  • Files can be transferred quicker
  • Files can be read from or written to quicker
• What are the types of secondary storage?

  • Magnetic storage
  • Optical storage
  • Solid state storage