בעל אוב וידעוני Art Scroll 53a2 note 21 says that
these are two different ways of communicating with the dead. This will
be more fully described on 65a (Rashi)
מכשף Art Scroll 53a2 note 29 Rashi points to 67a-67b as to what is included in this category.
There are various English translations as to what they mean, but the gemara is a better source.
Art Scroll 65a1 Mishna
בעל אוב זה פיתום המדבר משחיו - this is a Pitom who speaks from his
armpit 1
1 Pitom is a necromancer i.e. one who communicates with
the dead. He does this by raising the spirit of a deceased from the
ground and causing it to take up residence under his armpit, from
where its voice emanates (Rashi; see Tiferes Yisrael #68; cf.
Rambam and Raavad, Hilchos Avodas Kochavim 6:1, with Lechem Mishna;
see also 65b note 11.
Next the mishna says
וידעוני זה המדבר בפיו - this is one who speaks through his mouth
2
2 The Gemara (65b) explains that this sorcerer takes a bone
of the animal known as Yadua and places it in his mouth, from where
a voice then emanates (Rashi, see also Rambam, ibid, #2).
The Mishna in Art Scroll 67a3 Note 28 say that a מכשף (a sorcerer) who actually does something, is subject to the death penalty. However, if he only creates an illusion, he has violated a prohibition, but is not subject to the death penalty.
28 [Literally seizes the eyes.] Only a sorcerer who
actually does magic is liable to stoning, not one who creates an
illusion of a supernatural act while actually doing nothing.
According to Rambam (Sefer Hmitzvos, Negative Commandment 32), the
term האוחז את העינים refers to one who practices sleight of hand.
[Although one who creates illusions or practices sleight of hand is
not liable to the death penalty, he transgresses a prohibition
(*Rambam ibid. and Hilchos Avodas Kochavim 11:9; see also Kesef
Mishneh to ibid 11:15; *Yoreh Deah 179:15 with Shach #17)
29 I.e. two sorceres may be acting on a patch of cucumbers
and causing the cucumbers to gather in one area
30 Only the one who actually gathers the cucumbers through
sorcery is liable to stoning, not the one who creates the illusion
that they gathered while in reality they did not move (Rashi)
Art Scroll 67a4 note 34 points out that the reason the pasuk refers to מְכַשֵּׁפָה (female) is because the most prevalent practitioners of this were women, but both men and women who do this are subject to stoning.
