K comes from the Greek word kilo which means a thousand. The Greeks would likewise show million as M, short for Mega. So if we stay consistent with the Greek abbreviations, then billion would be shown as a letter G (Giga). Think of your computer expressing bytes of memory as kilobyte, megabyte, or gigabyte.

K was brought into the Latin alphabet with the name ka /kaː/ to differentiate it from C, named ce (pronounced /keː/) and Q, named qu and pronounced /kuː/. In the earliest Latin inscriptions, the letters C, K and Q were all used to represent the sounds /k/ and /ɡ/ (which were not differentiated in writing).

The symbolism of K. The « K » concept comes from the ancient Egypt dictionary where the letter K signifies peace, serenity, calm, and harmony. Ka symbolizes vital force maintained by food, represents the principle of life and energy. The king could not proceed to the important acts of worship without his Ka.