In the upcoming episode “Beyond the Wall,” Jon Snow and his party are headed North on a mission to try and capture a wight. In “Eastwatch,” Tyrion proposed that a wight can be brought to King’s Landing to convince Cersei, and everyone else, that the threat of the Undead is real.
White Walkers are terrifying since they killed the men of the Night’s Watch in Season 1. Over the course of the series, the Army of the Undead grew. In the premiere episode of Season 7, there were giant-wights, horse-wights, and White Walkers, all headed South led by the Night King.
But, what exactly is the difference between a White Walker and a wight?
History
The White Walkers were created thousands of years ago by the Children of the Forest. Bran witnessed this in one of his visions. The Children forced a piece of dragonglass into their captive’s chest and became the Night King. When Bran confronted Leaf regarding the creation, Leaf explained that they were at war against the First Men.
The First Men arrived from Essos and began clearing land and cutting down trees – including the weirwood trees, which infuriated the Children. The Children fought against the First Men, and being few in numbers, the Children decided to make a weapon, the White Walkers.
After 2000 years of conflict, the two sides agreed on The Pact and lived in peace for a long time.
Until the White Walkers broke free from the Children’s control 8000 years before Robert Baratheon’s Rebellion. They descended from far North and became a threat to anything living.
The Children and the First Men worked together to fight their common enemy – War for the Dawn. The White Walkers were defeated and were driven to the Far North.
With the help of the Children and giants, the Wall and the Night’s Watch were created should they come back again.
Currently, the White Walkers and the wights are marching south. It is not yet known what they want, or what their goal is.
Which is which
Both wights and White Walkers have glowing blue eyes. White Walkers created the wights, reanimating dead bodies to use as pawns and minions for their army.
They are literally mindless zombies, who are under the control of White Walkers – mainly the Night King (as shown in Season 5’s Hardhome).
The wights’ appearance can range from fresh-dead-body to just skeletons – like the one that killed Jojen Reed. Humans are not the only ones who are turned into wights, there are horses, even giants, and maybe a dragon?
White Walkers are far more superior to wights, they are not mindless zombies. Everything they touch freezes and turn into ice. They also have superhuman strength. The Night King has the power to turn people into White Walkers, like what he did to one of Craster’s son.
Weaknesses
In Season 3, Samwell Tarly discovered that dragonglass can kill a White Walker, and in Season 5, Jon Snow discovered that Valyrian steel can too.
While there isn't much Valyrian steel left, Jon has mined dragonglass from Dragonstone, to be used for weapons.
Wights are easier to kill but still difficult as they cannot be killed by decapitation since they are already dead. They are, however, susceptible to fire. This is also why Wildlings burn their dead, so their bodies don’t turn into wights.
During the War for the Dawn, it was said that Azor Ahai fought and defeated the White Walkers using his sword, Lightbringer. The sword was said to glow and radiate heat, if this is anything like Beric Dondarrion’s flaming sword, it can be another weapon against the enemies.
