Where does the term halo come from?

Answer 1

Halo refers to the halo ring of which is the center of the halo 1, 2 and 3 games. Halo is a term which often refers to the metaphorical good will of others, if someone is said to have a halo above their head it depicts the person's good spirit very much reflecting their personality. Angels are depicted to have a halo above their heads.

HALO is also used to refer to a military abbreviation for the term Hight Altitude Low Opening. A HALO jump is when paratroopers jump from a high elevation (tens of thousands of feet) and deploy their shoots at the last minute. An example would be jumping from 25,000 feet and opening your shoot at 2,500 feet. This is incredibly dangerous because even though you fall at terminal velocity (9.81 m/s2), you drastically decrease the time your parachute has to slow you down. There are two advantages to a HALO jump, though. One, the higher in the sky your plane, the longer it takes for the enemy to get a visual on your plane. And two, the closer you deploy your chute to the ground, the less time YOU will be visually noticed by the enemy.

Note that while it is incredibly difficult to see a person falling from the sky, it is not impossible. And if you are spotted, chances are someone is going to come investigating. It's not every day that people just fall from the sky.