Guardian Fairies (also known as Guard Fairies Guard Faes Guard Faeries Guard Feys Guard Fair Folks Guardian Faes Guardian Faeries Guardian Fays Guardian Feys and Guardian Fair Folks) are the Fairies who are guardians of the magical universe. Once Fairies reach their Enchantix level and graduate from Alfea, they also get the title of Guardian Fairies of the Magic Dimension. After this, they are bound to protect the Magic Dimension and fight its enemies and the forces of evil.
It is possible that once Witches graduate from Cloud Tower they also become Guardian Witches since, according to Griffin, the witches also fight evil, except that they use dark magic while fairies use light magic.