From which language does the "giga" in "gigabyte" originally come?

Giga, represented by the symbol G, is a unit prefix in the metric system denoting a factor of one thousand million (1,000,000,000). When referring to information units in computing, such asa gigabyte, the “giga-“ prefix usually means 1,073,741,824, in other words, 2 to the power 30. This might seem to cause ambiguity, but it is in line with other units commonly used in computing. These all have roots in binary digits. So, one kilobyte is not 1,000 bytes but 1,024 bytes (1,024 = 2 to the power 10); one megabyte (MB) is 1,024 kilobytes and one gigabyte is 1,024 megabytes.

According to the Oxford English Dictionary the earliest written use of the prefix “giga-“ as a prefix for one thousand million was in the Reports of the International Union of Pure and Applied Chemistry 14th Conference (published 1947). But there is an earlier use which comes from the International Electrotechnical Commission: in the 1920s a German member of the Commission made the suggestion of using “giga-” based on verses written by the German humorous poet Christian Morgenstern.

However, German was not the original language for the prefix “giga-”. “Giga” originally comes from the Greek word γίγας (“gígas”), meaning "giant". So, literally the word “gigabytes” means “giant bytes.”