Unified Earth Government

The United Earth Government or the UEG is the central civilian government for Earth and the colonies. The UEG houses the Colonial Administration Authority, and therefore the UNSC.

History
The United Earth Government came to existence at the conclusion of the Interplanetary War which occured in the 2160's. The war was fought between the United Nations, the Koslovics and the Frieden. The UN won the war and thus formed the UEG and the UNSC.

Differences Between the UEG and UNSC
The UNSC is the exploratory, scientific, and military arm of the human government. The UEG is responsible only for Earth and the colonies, the main locations of human government. The UEG would house the executive, legislative, and judicial branches of government, leaving defense the responsibility of the UNSC.

Trivia

 * It should be noted that both the UEG and UNSC are references to the human government and military in the early Bungie game, Marathon. See List of Marathon references in Halo.