primary and secondary storage

primary and secondary storage

1. optical storages

   • CD,DVD,BLURAY
   • a track of pits spirals from the center edge of the disc. read by a laser and lens, this pattern is converted into binary data steamsthat can contain digital text
   • advantages
     • >cheap to manufacture > very portable > widely availble

2. Solid-State Drive (SSD)

   • SD CARDS and USB sticks
   • a grid of electrical cells divided into sections called pages and then into blocks are used to end and recieve data
   • advantages
     • >faster read/write access than magnetic > small size >no moving parts > ideal fro USB and other portable devices

3. Magnetic storage

   • hard drives contain spinning magnetic discs, accessed by an arm that moves accross the surface to read and write data
   • desk tops network storage back up systems large document files
   • advantages
     • > high capacity at low cost > fast data access

4. RAM

   • (random access memory)
     • is a temporary area that a computer uses to store data in use

5. ROM

   • (read only memory)
     • provides a computer important instructions that do not change

6. virtual memory

   • when the RAM is full up by currently running programs and data the part of the hard drive designed as temporary RAM stores more data