Short answers, pulled from the story.
Lightning is a natural electrostatic discharge between two electrically charged regions in the atmosphere, sometimes with the second region on the ground. It forms in thunderstorms when rising ice crystals collide with graupel, charging the upper cloud positively and the lower cloud negatively until the difference discharges as a flash.
The air around a lightning flash rapidly heats to about 30,000 degrees Celsius, and the core of the plasma channel during the return stroke may exceed 50,000 degrees Fahrenheit. That sudden heating makes the air expand explosively, producing a shock wave heard as thunder.
Positive lightning is a cloud-to-ground flash that transfers positive charge to the ground and makes up less than 5 percent of all strikes. It is more dangerous because it produces higher peak currents, up to 400 kiloamperes, along with long continuing currents that raise the chance of starting a fire.
Lightning strikes most often over Lake Maracaibo, where the Catatumbo lightning phenomenon produces 250 bolts a day on average 297 days a year. The second most active spot is near the village of Kifuka in the eastern Democratic Republic of the Congo, receiving 158 strikes per square kilometer each year.
Lightning occurs at an average frequency of about 44 times per second, give or take 5, which equals nearly 1.4 billion flashes per year. About 70 percent of these strike over land in the tropics, where atmospheric convection is greatest.
Yes, lightning can and often does strike the same place more than once, making the common saying a myth. It is more likely to strike prominent or conductive objects, and the Empire State Building in New York City is struck on average 23 times per year.