Self-explanatory title. I really don't know what any of them mean anyway, so a li'l definition of each of the terms would be greatly appreciated.
Okay, ill make it simple for you, assuming you know the difference between a humbucker and a single coil.

Coil tap - This is when you use two single coils at the same time to make a fatter sound ( positions 2 and 4 on a strat)

Coil Switch - This is pretty self-explanitory, just changing the coils that you are currently using (Neck, Bridge, Middle)

Coil Split - This is when you have humbuckers in your guitar and you pull up a tone know that splits the humbucker into a single coil. This will provide a different sound, although if you have ceramic magnets as opposed to alnico, it wont truly sound like a normal single coil.

Hope that cleared everything up for you
^you are mostly right.

A coil tap is when you have a line out somewhere in the middle of the coil. For example, you can have 1 single coil pickup that is wound to 12K with a tap at 7K. That means that you can switch between a 12K pickup and a 7K pickup.

Coil split is when you turn off 1 coil of a humbucker. This never sounds like a "normal" single coil, but high output humbuckers with alnico magnets do get a little closer to sounding like single coils.
Not taking any online orders.
explaining coil tapping in a less technical way... it means that there are extra windings in the pickup that you can "tap" into or out of. Getting those exta windings of wire gives you a hotter, more aggressive sound with less sustain, like SRV.

You usually access a coil tap with a push/pull knob or a button that's built into the tone knob. Don't pay attention to the first answer on coil tapping.
Okay, I've understood the coil-splitting part, but I'm a li'l confused on the tapping. Is it that any pickup can be coil-tapped, or are there special humbuckers that have the extra windings (I've never heard of a single-coil being coil-tapped BTW) ?
A coil tap has to be installed when the pickup is made. It can not be done on any pickup. Typically they are only done on single coil pickups but they can be done on humbuckers as well.
Not taking any online orders.
to my knowledge* usually only humbuckers are available for tapping b/c the point of tapping them is to get the single coil "sound". so to tap a single coil wouldn't make sense? but seeing as i dont know too much, dont take my word for it there are people who know a lot more about it. i hope that helped.
coil tapping is done almost exclusively on single coils. If it is done on humbuckers, I've never heard of it. Usually when someone talks about coil tapping a humbucker it means they're confusing tapping with splitting.
Oh god I'm getting confused by the second. I think I'll have a look at the list of "trustworthy" UG-ers on this forum, since each and every one of you have an explanation that contradicts the other's! =S

EDIT: Gaaaah, nevermind!
Last edited by Uphill_Battle at Mar 25, 2007,