Proper charas is hand rubbed hash, made from resin collected from live plants - as opposed to all other types of hash that are made from dead/harvested plants. This gives it a notably different high, very cerebral and active... sometimes very intense. Manalis can very good indeed, Malana too, good Nepalese is on similar lines. The real deal isn't abundant though; the only way to be sure is going to a reputable coffeeshop and paying reassuringly high prices
Then there are other asian black hashes that aren't made from live plants. The cheap ones are often adulterated. But a decent one will give a nice heavy stone.
Moroccan/Lebanese brown/red/blonde hashes are made from sun dried plants, the resin is sifted and pressed into chunks. Again, this gives a different (usually lighter) buzz.