1.2 Memory and Storage

Primary storage

Holds data and programs currently in use.

RAM

Volatile memory lost when power is off

ROM

Non-volatile memory essential for booting.

Virtual memory

Data transfer between RAM and secondary storage.

Cache

Temporary storage for frequently accessed data.

Secondary storage

Long-term storage for data and programs.

Optical storage

Uses lasers to read/write data (e.g., CD/DVD).

Magnetic storage

Uses magnetic fields to store data (e.g., HDD).

Solid state storage

Uses flash memory (e.g., USB drives).

Bit

Smallest unit of data, 0 or 1.

Nibble

4 bits, half a byte.

Byte

8 bits, basic data unit.

Kilobyte

1,000 bytes or 1 KB.

Megabyte

1,000 KB or 1 MB.

Gigabyte

1,000 MB or 1 GB.

Terabyte

1,000 GB or 1 TB.

Petabyte

1,000 TB or 1 PB.

Sound file size

Calculated by sample rate x duration x bit depth.

Image file size

Calculated by colour depth x height x width.