Primary Memory
https://letsknowaboutcomputer.blogspot.com/2011/10/primary-memory.html
Memory BasicsIf your computer's CPU had to constantly access the hard drive to retrieve every piece of data it needs, it would operate very slowly. When the information is kept in memory, the CPU can access it much more quickly.
As you can see above, the CPU accesses memory according to a distinct hierarchy.
Most data goes in random access memory (RAM) first. The CPU then stores pieces of data it will need to access, often in a cache, and maintains certain special instructions in the register.
You turn the computer on.
The computer loads data from read-only memory (ROM) and performs a power-on self-test (POST) to make sure all the major components are functioning properly.
The computer loads the basic input/output system (BIOS) from ROM. The BIOS provides the most basic information about storage devices, boot sequence, security, Plug and Play (auto device recognition) capability and a few other items.
The computer loads the operating system (OS) from the hard drive into the system's RAM.
When you open an application, it is loaded into RAM. To conserve RAM usage, many applications load only the essential parts of the program initially and then load other pieces as needed.
When you save a file and close the application, the file is written to the specified storage device, and then it and the application are purged from RAM.
As you can see above, the CPU accesses memory according to a distinct hierarchy.
Most data goes in random access memory (RAM) first. The CPU then stores pieces of data it will need to access, often in a cache, and maintains certain special instructions in the register.
The computer loads data from read-only memory (ROM) and performs a power-on self-test (POST) to make sure all the major components are functioning properly.
The computer loads the basic input/output system (BIOS) from ROM. The BIOS provides the most basic information about storage devices, boot sequence, security, Plug and Play (auto device recognition) capability and a few other items.
The computer loads the operating system (OS) from the hard drive into the system's RAM.
When you open an application, it is loaded into RAM. To conserve RAM usage, many applications load only the essential parts of the program initially and then load other pieces as needed.
When you save a file and close the application, the file is written to the specified storage device, and then it and the application are purged from RAM.
