Many are always asking for the actual difference between the two, or at least the up to date and valid definitions.
I think there are multiple ways to define them both, some more questionable than others but in the end I'd say it's a matter best left to personal belief. However, aside from how people personally define there is how people personally understand it and then explain it. I believe just as with many other concepts even the people who answer the questions tend to not understand it themselves.
Sad, but true.
Well there are some misconceptions I'd like to clear up to assist you in developing your own definition.
Person- "Magic does not have colors."
Me- "Are you drunk?"
If and when we refer to magic with the colors black or white we are not saying in any way at all that magic is actually colorful.
No, just get that retarded idea out of your head.
Color is given to magick simply for categorizing it. Not saying that it has color, for categorizing it.
Read that last sentence very carefully!
Person- "Black or dark usually means evil. White or light usually means good."
Me- "Have you met the two women many call Hera and Nyx?"
Black does not mean evil magic that is used to harm other beings.
White does not mean good magic used to help other beings.
Magic is never evil nor good. It is all in the intent of the user.
Person- "One way to look at it is black magic is what is used for personal benefit and white magic is what helps others."
Me- "Weren't you going on about Karma a moment ago?"
All magic is cast with some kind of personal gain, pretty much no exceptions. Any kind of magic may be cast and have the effect of benefiting someone else, even a curse. You have something called consequences, everything you do including with magic has consequences. There is no way to measure how much something might backfire and there is no way to completely measure how much effect something might have on the rest of the world. Magic is manipulation of natural energy, to use it is to affect reality outside the manner it was naturally carrying on. If you cast a healing spell, that is still black magic by this definition because you have the personal satisfaction of helping someone even if by some chance they don't want to be helped. If you cast a healing spell it may still be considered white magic by this definition even if the person them self doesn't want to be healed, but perhaps someone else does and they become satisfied.
You never know who you are really truly pleasing except for yourself.
Person- "Categories in magic don't exist."
Me- "Now I know you're retarded or something."
Categories have and probably always will be used in magic, it just helps make things easier to understand. I see people here all the time trying to work against traditional ways of doing things because they feel their methods are best. I strongly suggest against listening to these people because they are most certainly not right all the time and do not know everything.
Categories can be confusing though, because the definitions or classification of those categories can differ greatly between individuals so often times there's some misunderstanding.
This should not make it wrong to use categories, it should only provide you with initiative to do proper research and decide on your own, valid method of definition.
Oh and it helps to specify what you mean when speaking to other people. ;)