The One Power is divided into five seperate powers called threads. These threads are named according to what can be done with them. The five threads are: Earth, Air, Fire, Water, and Spirit. Channelers have strengths and weaknesses with different threads of the One Power. Most are the strongest in one or two and weaker in the others. Also, strengths in certain
threads seem to be seen mainly in only one gender. For example, mostly only men are strong in Fire and Earth. This is true for Air and Water for women. Both genders are equally strong in Spirit.

The One Power is divided in half. The two halves are Saidar and Saidin. Saidar is that part of the One Power that women can channel and Saidin is the half of the One Power that men can channel. The part of the One Power called Saidin was tainted by the Dark One in his backlash on Lews Therin during the breaking of the world. The taint of Saidin is like a horrible slime on the surface of water that must be reached through to get to the wanted source. All men the channel are doomed to either go mad or die of a horrible wasting sickness.

Women who think  they might have the ability or who are wilders can go to the White Tower for training. Women are then tested to see if they have the ability. To do this, a trained Aes Sedai channels to create a small flame between herself and the woman being tested. If the woman has the ability to channel or learn to channel she will feel a resonance.There over a process of many years they are tought as much of the One Power as possible. They begin as Novices, and when it is thought they are ready, they go through the three arches to become Accepted. When an accepted is ready to be raised to Aes Sedai they must swear the Three Oaths on the Oath Rod. The first oath is to speak no word that is not true. The second oath is to make no weapon with which no man may kill another. The third oath is to never use the One Power as a weapon except against Shadowspawn, or in extreme defense of one's self or Warder or another Aes Sedai.
 

Men who think they could channel go to the Black Tower. This is a safe haven for them where they do not have to be afraid that the Red Ajah will gentle them. To be gentled is to be cut off from the One Power so that you can never channel again.  The testing for men is exactly the same as women.Here they are trained to become living weapons. These men start as Soldier and then they progress to Dedicated. An Asha' man is the male equivalent of an Aes Sedai.

To complete acts with the One Power that require more strength than any one person could possibly have on their own, you can link. People link to form circles that are controlled by one person. These circles can be extremely powerful. Another way to increase strength is to use an angreal or a sa'angreal. These are objects of the power that greatly increase the amount that a single person could channel safely. To use either of these you simply have physical contact with it and draw the One Powe through it.

The best known channelers are those of the White Tower called Aes Sedai who often take part in many matters of war, peace, and other dealings between nations. There are many other groups of those who can channel. There is the group called the the Kin in Ebou Dar and there are the Windfinders on the ships of the Sea Folk; both of these groups are channelers. Other channelers can be found among the Aiel Wise Ones, and the suldams and damanes of the Seanchan can also channel. Those who channel are often feared by others and also outlawed. This just shows the enormous influence of the One Power on the world.