What is used for holding program instructions that can't be changed throughout the life of the computer?

The correct answer is ROM.

Key Points

• ROM
  • Read-Only Memory is a ROM in a computer.
  • Read-only memory is a storage medium that permanently stores data on computers and electronic devices.
  • The data stored in these chips is nonvolatile i.e. it is not lost when power is removed.
  • There are five basic ROM types:
    • ROM: Read-Only Memory.
    • PROM: Programmable read-only memory.
    • EPROM: Erasable programmable read-only memory.
    • EEPROM: Electrically erasable programmable read-only memory.
    • Flash memory: Flash memory, a type of EEPROM that uses in-circuit wiring. 
  • BIOS uses Flash memory.

Additional Information

• Register
  • The smallest and fastest memory of a computer is registered memory located in the computer's central processing unit(CPU).
  • It generally stores the most used instructions, data, etc. which are to be used by CPU.
  • Control Unit is part of the CPU.
  • It advises the input and output devices, and computer memory on how to respond to the instructions sent to the processor.
• RAM
  • It stores data that the computer needs to use temporarily. So it is faster than the secondary storage devices. It is a volatile memory i.e. the data disappear from it when the power is off.
  • It is known as the Read-Write Memory. i.e. the user can write information into RAM and read information from it.
  • It is called random access since any memory location can be accessed randomly for reading and writing. The access time is the same for each memory location.
  • It is usually called “temporary” memory, which means that when the system is shut down, the memory is lost.
• Cache
  • A cache memory is used by the central processing unit of a computer to reduce the average cost time or energy to access data from the main memory.
  • Generally Cache memory is logically positioned between CPU and main memory.