Cunning Men/Cunning Women, were professional practitioners of folk magic found in many parts of the Europe throughout the latter middle-ages and up into the twentieth century. The term "cunning" is a synonym for wise or crafty.
Cunning men and women were believed to be skilled healers, knowing the properties of the plants that grew in the area and were believed to be able to help with life's problems, such as finding a mate, reconciling lovers, recovering lost objects, ensuring fertility and prosperity, and achieving justice. Cunning men and women were for the majority of the population of the time, the only medical "professionals" people visited. Many cunning women were also trained midwives.
Cunning men and women should not be confused with witches. Instead, and like with the similar traditions of folk magic like hoodoo/rootwork/conjure, cunning men and women were closer to "witch doctors", meaning that it was their job to fight witchcraft, remove evil spells, and heal sickness caused by witches. The belief that cunning men and women were witches stems mainly from Wiccan propaganda.
Unfortunately starting in the 1950s with the birth of the Wiccan religion, various proponents of Wicca began to claim cunning men and cunning women as their spiritual ancestors. This process of assimilating the cunning tradition into Wiccan mythology entailed the rewriting of history. Cunning men and women were not Wiccans, nor were they pagans. They were Christians and prayed to the Christian God and used the bible in their works.
Many cunning men and women were falsely accused of being witches and were persecuted, tortured, and executed during the witchcraft hysteria of the middle ages. Please keep in mind that not every accused witch was a cunning man or woman, but many of them were. Likewise, most of them were innocent of the crime of witchcraft and were instead simply used as scapegoats for any number of reasons by their communities.
Note: Though the word cunning is indeed a synonym for wise, the word witch is not. The word witch does not mean "wise woman" and has never held a positive connotation. Today there are people who still claim to practice the cunning tradition though most of the individuals are Wiccans or other self-styled witches and have little to nothing to do with the actual cunning tradition of centuries past which may now be extinct.