Winx Club Forever
Though they have been shown in the series, it is unknown whether they are simply male counterparts of witches or an entirely distinct race, as no wizard has ever been shown at Cloud Tower. It could be possible that Wizards are trained at Red Fountain (in the Cinélume version, Red Fountain was called as "the school for wizards in training") and as some Red Fountain students have already displayed signs of magical ability in the usage of magical technology and in controlling the Red Fountain dragons.
Similarities to Witches and Fairies
Wizards have been shown to have specific powers, especially in the case of Valtor, who is a Wizard of the Dragon's Flame, the Black Circle, where Ogron, Duman, Anagan and Gantlos have Hatred, Greed, Destruction and Envy and have the powers of absorbing magic, shape-shifting, super speed and sound manipulation respectively; Acheron, who is a Supreme Wizard and creator of the Legendarium and Brafilius, who is a Wizard of the Animals. Wizards can also choose to align themselves with either light or darkness, like fairies aligning themselves with light and witches aligning themselves with darkness.
Powers and Strength
The power sources of Avalon, Saladin and Nabu have not been specified, though Saladin and Nabu both interestingly use their magical staffs at a great extent, and it could be that Nabu and Saladin are from a different type of wizards than that of Valtor, the Wizards of the Black Circle, Acheron and Brafilius.It is an interesting to note that wizards also align themselves with either light or darkness. For instance, though he and Bloom both possess the power of the Dragon Flame, Valtor was created by its dark side, often utilizing his mark to control others.
Like witches and fairies, wizards have powers specific to them. Wizards can also converge their magic with witches and fairies if their strong enough.
Acheron also known as a dark wizard and the creator of the Legendarium and a powerful sorcerer, he can invoke any powerful creature to attack its enemy, uses dark magic on Earth from the terrestrial witches in order to become the greatest sorcerer in the Magical Universe, he was able to do things like teleport Selina to the Lost Library of Alexandria. When he was free from the Legendarium, he was able to create lightning and bursts of dark magic and also showed to be powerful enough to send the Trix into the Legendarium and make Cloud Tower fall. He was able to rid the entire Magic dimension of its magic. He can also create some dark magic to protect himself (to hold Bloom's Dragon Flame). When he created the Legendarium, he was stronger than his opponents (except for the Dragon's Flame, with the Winx's Bloomix).
Saladin on the other hand, uses his powers to protect and defend good from all evil, evident in his incantation when fighting the Army of Darkness at Red Fountain during season 1 and when he uses his powers, they are often displayed in colors of light.