there are major differences. first, cocaine is like a whole bunch of toxic substances (including str8 gasoline) that kind of give you a boost. the only thing natural in it is the coca leaf, but its mashed up and, its usually kind of powdery. on the other side, meth, glass, crystal etc. is kind of transparent looking, sort of clear, and the higher quality stuff kind of "chards" up like little broken pieces of glass, hence the term "glass"
in order of their potency: crank, speed, which are simply
amphetamine or
dexamphetamine. then there is meth, crystal meth, glass, and they all have various amounts of the same chemical,
d-N-methylamphetamine, and then there is ice (ice is a different substance entirely and CANNOT be snorted, must be smoked, and its name is
4-Methylominorex). if you look at the names alone, they are similar. cocaine is known as
benzoylmethyl ecgonine, completely different.
all this may seem like gibberish, so ill talk bluntly now. if you do both types, which i have in some form, youll find out that the Euphoric stimulant of cocaine and/or crack differs mostly from the psychoactive stimluant of speed and crystal in their effects because
coke mainly works on endorphins, while the
speed works on the dopamine synapse. endorphins (coke) make you feel really good, suh as if you were already having sex, while the speed (dopamine) makes you feel really ambitious, creative and everything is clear and intense, or shiney. another major difference is you can have sex on meth, but often times it is hard to have good sex on cocaine, because the endorphins are already being used up.
about the only two things they have in common are that they give you a boost of energy and that you can snort them. oh yeah, they are also both schedule 1 narcotics controlled by the DEA. you knew that. hehe
i hope this answers your questions.