The idea of a witch, etymologically going back to old Anglo-Saxon roots, seems to be considerably older than the famous witch persecutions of the early modern period. So how would a Medieval Englishperson have conceived of a witch?
Were witches simply regarded as an antiquated pagan superstition, or possibly a suitable fictitious monster for bedtime stories?
Did people think witches were real, but that they were obviously monsters (along the lines of a hag from Dungeons & Dragons or Grendel's mother from Beowulf or the like), so there would be no suspicion that, say, a cantankerous old woman who isn’t a green-skinned monster with sharp teeth might be a witch?
Or did popular conceptions of witchcraft not change much compared to the early modern period, and it was mainly the ecclesiastical and judicial authorities converging toward the popular view that changed? Would a Medieval peasant or baker have ideas broadly similar to those of early modern conceptions like the Malleus Maleficarum, even if contemporary priests or judges would have largely dismissed them?
This need not apply solely to Medieval England, and could apply to other pre-Early Modern periods in Britain (Anglo-Saxon, Brythonic, Roman), or to places outside of England that went on to take part in the EM witch craze (Holy Roman Empire, Poland, Sweden, etc), or both.
An early medieval English reference to witches comes from the 11th Century penitential known as the Scrifboc:
X14.05.01 If a woman practices magic and incantations and sorcery and the like, she is to fast 12 months or the 3 40-day fasting periods or 40 nights; one should ascertain how great the sin is.
X14.08.01 A woman who mixes a man's seed in her food and then eats it so she be more agreeable to the male is to fast for 3 winters.
X14.09.01 A woman who performs an abortion on her foetus in her womb and kills it, if it is about 40 nights since she received the seed, before it expired, she is, like the murderer, to fast 3 winters and every week is to keep the 2 fast days until evening and observe the 3 fasting periods.
That these penances are grouped together suggests that there was a relatively thin line between elements of what we might now call 'folk medicine' and what was perceived as witchcraft. A residual belief in the supernatural remains professionally well into the period; the 9th century medical textbook known as Bald's Leechbook contains means for alleviating curses and Elvish magic alongside its more typical treatments for trauma, infections, fevers, and the like. Alongside the more 'respectable' obstetric medicine included in the Leechbook, the Scrifboc infers a practice of what could be called 'midwifery' on a more prosaic level. This is a relatively common phenomenon: in a small community where infant mortality and death in childbirth are depressingly real concerns, it could be expected that older, more experienced women maintain a corpus of experience and knowledge on sexual health; if this happened to include means of inducing an abortion - information which was certainly known to but deemed inappropriate for a medical textbook like the Leechbook - it's easy to see how the contemporary Church could easily deem such a practice as witchcraft.
The wider practice of incantations, 'sorcery' and elements of blood magic are not touched on in detail, but it's clear that this is a more 'everyday' form of magic: more 'supernatual' potions and charms and curses rather than flying around on broomsticks or turning people into newts.