• is a special type of variable
• storing the address (memory location) of another variable

The number of memory cells needed for a pointer depends on the computer's architecture:

• Old computer, or hand-held device with only 64KB of addressable memory:
  • 2 memory cells (i.e. 16 bits) to hold any address from 0x0000 to 0xFFFF (= 65535)

• Desktop machine with 4GB of addressable memory
  • 4 memory cells (i.e. 32 bits) to hold any address from 0x00000000 to 0xFFFFFFFF (= 4294967295)

• Modern 64-bit computer
  • 8 memory cells (can address 2⁶⁴ bytes, but in practice the amount of memory is limited by the CPU)