Memory & Storage

Memory & Storage

1. RAM

   • RAM is short for 'random access memory'.
   • It is the place where all the programs and data is stored in a computer.
   • RAM allows the computer to quickly access programs and data.
   • RAM is quicker to read to and write from than any other storage in a computer, such as the hard disk.
   • The items in RAM only stay there as long as the computer is turned on.
   • RAM is 'volatile memory'.

2. ROM

   • ROM is short for 'read only memory'.
   • ROM contains the programs that allow your computer to 'boot-up'.
   • The data and programs stored in ROM are not lost when the computer is turned off.
   • ROM is 'non-volatile' memory, which means it is permanent.
   • ROM is smaller in memory capacity than RAM is.

3. Flash Memory

   • Flash memory is a type of non-volatile memory. This means it will retain its contents even without any power.
   • Flash memory is described as a solid-state storage device as it has no moving parts.
   • As flash memory has no moving parts, it tends to be more robust than a hard disk.
   • Flash memory is made up of cells that contain storage transistors.
     • They contain logic gates.
     • Electrons and positive and negative charges are used to write and erase data to and from the flash memory.

4. Virtual Memory

   • Virtual memory is a feature of an operating system. It allows the hard disk in the computer to act as an extension of RAM.
     • It allows sections (called pages) of data to be stored in the hard disk.
     • A computer will make use of this feature when it is running out of space in the RAM.
     • The operating system will temporarily move pages of the data to be stored in the hard disk.
       • This process is known as paging.
   • When it needs these pages again it will switch them with some of the pages that are not currently in use in the RAM.