He killed the villain Krona, who was a former Guardian of the Universe (The race of immortal beings who created the rings, also known as Oans). Fearing that Hal's killing of Krona would prompt him to possibly kill the other Guardians, they stripped him of his ring and sent him back to Earth.
In an episode of "The Batman" called Ring Toss, Penguin somehow gets ahold of Hal Jordan's Green Lantern Corps ring and uses it to fly around and do stuff. Batman eventually beats Penguin and gets the ring back, using it to fly once before returning it to the rather annoyed Hal Jordan.
The Green Lantern Corps is an intergalactic organization dedicated to preserving order throughout the universe. Abin Sur was the appointed Green Lantern in the region of the galaxy that includes Earth. When he crash-landed on Earth and realized he was dying, he chose Hal Jordan, a California jet test pilot, as his replacement. Hal had the qualities required to be a Green Lantern: he was fearless, honest, and had strong willpower. Abin Sur gave Hal his Power Ring (which projects a green energy that can form anything the wearer can imagine) and Power Battery (a device resembling a lantern, needed to recharge the ring every 24 hours) before he died.
The original Green Lantern was Alan Scott, a character with a ring and lantern that gave him mystical abilities. In 1959, DC Comics re-imagined the Green Lantern idea and replaced Alan Scott with a new one, Hal Jordan. This Green Lantern had a completely different backstory and a different set of abilities derived from a power ring given to him by a dying alien member of an interplanetary police force. It is this Green Lantern and not Alan Scott that the modern Green Lantern iterations are based on.
HAL .
The most well-known Green Lantern of Earth is Hal Jordan. Other human Green Lanterns include John Stewart, Guy Gardner, Kyle Rayner, and Jessica Cruz. Each of them draws power from the Green Lantern ring.
He WAS the green lantern of space sector 2814 unti issue 67 in the conclusion of the green lantern war, where he killed the rogue guardian Krona and was discharged as a green lantern. Most likely after the events of Flashpoint this will be changed because in the Justice League #1 preview in the "DC Comics the New 52 book Hal Jordan makes an appearance as the green lantern of earth sector 2814
Green Lantern became a superhero after receiving a power ring from the Green Lantern Corps, an intergalactic police force. The ring grants its wielder extraordinary abilities, including flight, energy projection, and the power to create constructs from willpower. The character's origin varies, but most notably, Hal Jordan, a test pilot, was chosen for his bravery and strong will, embodying the Corps' motto of overcoming fear. This transformation into a Green Lantern allows him to protect the universe and uphold justice.
Hal Lamar went by Hal.
Hal Newhouser went by Prince Hal.
Hal Chase went by Prince Hal.
Hal Price went by "Happy" Hal Price.
Hal Baylor's birth name is Hal Brittan.