Spell Definitions--help! DADA spells?

[ebeth0000000000]

No: HPFGUIDX 71168

Can anyone accurately define the following for me:
1) Hex
2) Curse
3) Charm
4) Spell

This type of thing didn't used to bother me, but now I'm getting 
really confused.  

I know that in DADA the kids mostly study curses and counter-curses, 
but they also find things useful in practical DADA that would be 
considered 'charms' like wingardium leviosa (harry and the brains in 
the DOM)  Are spells strictly categorized, or is it all in how you 
use them?  Alohamora and Lumos--are those considered charms?  Or 
what??  Is Hex just another word for curse, or is a curse worse?  
hmmm. . .

Is anyone aware of an online resource that lists every spell the 
reader has been exposed to thus far in the canon? Like what it's 
called, what it does, what you have to say, etc?  Point me there!

Thanks,
EBeth